subject:(Ultrafast magnetism)

University of Wollongong

1. Hargreaves, Rhys. Ultrafast demagnetisation as a Terahertz source.

Degree: MS– Research, 2014, University of Wollongong

URL: ; https://ro.uow.edu.au/theses/4274

► Ultrafast demagnetisation of ferromagnets by ultrafast laser pulses provides a unique window for the investigation of spin dynamics in ferromagnets. Ultrafast demagnetisation has previously… (more)

Subjects/Keywords: Terahertz; ultrafast; spin dynamics; magnetism

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Hargreaves, R. (2014). Ultrafast demagnetisation as a Terahertz source. (Masters Thesis). University of Wollongong. Retrieved from ; https://ro.uow.edu.au/theses/4274

Chicago Manual of Style (16^th Edition):

Hargreaves, Rhys. “Ultrafast demagnetisation as a Terahertz source.” 2014. Masters Thesis, University of Wollongong. Accessed April 23, 2021. ; https://ro.uow.edu.au/theses/4274.

MLA Handbook (7^th Edition):

Hargreaves, Rhys. “Ultrafast demagnetisation as a Terahertz source.” 2014. Web. 23 Apr 2021.

Vancouver:

Hargreaves R. Ultrafast demagnetisation as a Terahertz source. [Internet] [Masters thesis]. University of Wollongong; 2014. [cited 2021 Apr 23]. Available from: ; https://ro.uow.edu.au/theses/4274.

Council of Science Editors:

Hargreaves R. Ultrafast demagnetisation as a Terahertz source. [Masters Thesis]. University of Wollongong; 2014. Available from: ; https://ro.uow.edu.au/theses/4274

University of California – Berkeley

2. Yang, Yang. Ultrafast Manipulation of Magnetic Order with Electrical Pulses.

Degree: Materials Science & Engineering, 2017, University of California – Berkeley

URL: http://www.escholarship.org/uc/item/4sm4032c

► During the last 30 years spintronics has been a very rapidly expanding field leading to lots of new interesting physics and applications. As with most… (more)

▼ During the last 30 years spintronics has been a very rapidly expanding field leading to lots of new interesting physics and applications. As with most technology-oriented fields, spintronics strives to control devices with very low energy consumption and high speed. The combination of spin and electronics inherent to spintronics directly tackles energy efficiency, due to the non-volatility of magnetism. However, speed of operation of spintronic devices is still rather limited (~nanoseconds), due to slow magnetization precessional frequencies.Ultrafast magnetism (or opto-magnetism) is a relatively new field that has been very active in the last 20 years. The main idea is that intense femtosecond laser pulses can be used in order to manipulate the magnetization at very fast time-scales (~100 femtoseconds). However, the use of femtosecond lasers poses great application challenges such as diffraction limited optical spot sizes which hinders device density, and bulky and expensive integration of femtosecond lasers into devices.In this thesis, our efforts to combine ultrafast magnetism and spintronics are presented. First, we show that the magnetization of ferrimagnetic GdFeCo films can be switched by picosecond electronic heat current pulses. This result shows that a non-thermal distribution of electrons directly excited by laser is not necessary for inducing ultrafast magnetic dynamics.Then, we fabricate photoconductive switch devices on a LT-GaAs substrate, to generate picosecond electrical pulses. Intense electrical pulses with 10ps (FWHM) duration and peak current up to 3A can be generated and delivered into magnetic films. Distinct magnetic dynamics in CoPt films are found between direct optical heating and electrical heating.More importantly, by delivering picosecond electrical pulses into GdFeCo films, we are able to deterministically reverse the magnetization of GdFeCo within ~10ps. This is more than one order of magnitude faster than any other electrically controlled magnetic switching. Our results present a fundamentally new switching mechanism electrically, without requirement for any spin polarized current or spin transfer/orbit torques. Our discovery that ultrafast magnetization switching can be achieved with electrical pulses will launch a new frontier of spintronics science and herald a new generation of spintronic devices that operate at high speed with low energy consumption.At last, to push ultrafast spintronics to practical use, ultrafast switching of a ferromagnetic film is desired. By exploiting the exchange interaction between GdFeCo and ferromagnetic Co/Pt layer, we achieved ultrafast (sub 10ps) switching of ferromagnetic film with a single laser pulse. This result will open up the possibility to control ferromagnetic materials at ultrafast time scale, critical for practical applications.

Subjects/Keywords: Materials Science; Electrical engineering; Physics; Ferrimagnets; Ferromagnets; Magnetism; Spintronics; THz; Ultrafast

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Yang, Y. (2017). Ultrafast Manipulation of Magnetic Order with Electrical Pulses. (Thesis). University of California – Berkeley. Retrieved from http://www.escholarship.org/uc/item/4sm4032c

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Yang, Yang. “Ultrafast Manipulation of Magnetic Order with Electrical Pulses.” 2017. Thesis, University of California – Berkeley. Accessed April 23, 2021. http://www.escholarship.org/uc/item/4sm4032c.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Yang, Yang. “Ultrafast Manipulation of Magnetic Order with Electrical Pulses.” 2017. Web. 23 Apr 2021.

Vancouver:

Yang Y. Ultrafast Manipulation of Magnetic Order with Electrical Pulses. [Internet] [Thesis]. University of California – Berkeley; 2017. [cited 2021 Apr 23]. Available from: http://www.escholarship.org/uc/item/4sm4032c.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Yang Y. Ultrafast Manipulation of Magnetic Order with Electrical Pulses. [Thesis]. University of California – Berkeley; 2017. Available from: http://www.escholarship.org/uc/item/4sm4032c

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Colorado

3. La-o-vorakiat, Chan. Element-Selective Ultrafast Magnetization Dynamics with a Tabletop Light Source.

Degree: PhD, Physics, 2011, University of Colorado

URL: https://scholar.colorado.edu/phys_gradetds/46

► Next-generation hard-disk drives will require smaller magnetic bits and faster magnetization switching; hence, better understanding of nanoscale magnetic material is one of the key… (more)

Subjects/Keywords: Demagnetization Dynamics; High-harmonic Generation; Magnetism; Ultrafast; Condensed Matter Physics

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

La-o-vorakiat, C. (2011). Element-Selective Ultrafast Magnetization Dynamics with a Tabletop Light Source. (Doctoral Dissertation). University of Colorado. Retrieved from https://scholar.colorado.edu/phys_gradetds/46

Chicago Manual of Style (16^th Edition):

La-o-vorakiat, Chan. “Element-Selective Ultrafast Magnetization Dynamics with a Tabletop Light Source.” 2011. Doctoral Dissertation, University of Colorado. Accessed April 23, 2021. https://scholar.colorado.edu/phys_gradetds/46.

MLA Handbook (7^th Edition):

La-o-vorakiat, Chan. “Element-Selective Ultrafast Magnetization Dynamics with a Tabletop Light Source.” 2011. Web. 23 Apr 2021.

Vancouver:

La-o-vorakiat C. Element-Selective Ultrafast Magnetization Dynamics with a Tabletop Light Source. [Internet] [Doctoral dissertation]. University of Colorado; 2011. [cited 2021 Apr 23]. Available from: https://scholar.colorado.edu/phys_gradetds/46.

Council of Science Editors:

La-o-vorakiat C. Element-Selective Ultrafast Magnetization Dynamics with a Tabletop Light Source. [Doctoral Dissertation]. University of Colorado; 2011. Available from: https://scholar.colorado.edu/phys_gradetds/46

University of Colorado

4. Gopalakrishnan, Maithreyi. Comparative Study of Laser-Induced Ultrafast Demagnetization Dynamics in Fe, Co, and Ni.

Degree: MS, Physics, 2016, University of Colorado

URL: https://scholar.colorado.edu/phys_gradetds/171

► Even twenty years after the discovery of ultrafast demagnetization of ferromagnetic materials induced by a femtosecond laser pulse there is still an ongoing debate… (more)

Subjects/Keywords: Harmonic; Laser; Magnetism; Spin; Temperature; Ultrafast; Condensed Matter Physics; Optics

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Gopalakrishnan, M. (2016). Comparative Study of Laser-Induced Ultrafast Demagnetization Dynamics in Fe, Co, and Ni. (Masters Thesis). University of Colorado. Retrieved from https://scholar.colorado.edu/phys_gradetds/171

Chicago Manual of Style (16^th Edition):

Gopalakrishnan, Maithreyi. “Comparative Study of Laser-Induced Ultrafast Demagnetization Dynamics in Fe, Co, and Ni.” 2016. Masters Thesis, University of Colorado. Accessed April 23, 2021. https://scholar.colorado.edu/phys_gradetds/171.

MLA Handbook (7^th Edition):

Gopalakrishnan, Maithreyi. “Comparative Study of Laser-Induced Ultrafast Demagnetization Dynamics in Fe, Co, and Ni.” 2016. Web. 23 Apr 2021.

Vancouver:

Gopalakrishnan M. Comparative Study of Laser-Induced Ultrafast Demagnetization Dynamics in Fe, Co, and Ni. [Internet] [Masters thesis]. University of Colorado; 2016. [cited 2021 Apr 23]. Available from: https://scholar.colorado.edu/phys_gradetds/171.

Council of Science Editors:

Gopalakrishnan M. Comparative Study of Laser-Induced Ultrafast Demagnetization Dynamics in Fe, Co, and Ni. [Masters Thesis]. University of Colorado; 2016. Available from: https://scholar.colorado.edu/phys_gradetds/171

University of Minnesota

5. Schliep, Karl. The Investigation Of New Magnetic Materials And Their Phenomena Using Ultrafast Fresnel Transmission Electron Microscopy.

Degree: PhD, Material Science and Engineering, 2017, University of Minnesota

URL: http://hdl.handle.net/11299/191448

► State-of-the-art technology drives scientific progress, pushing the boundaries of our current understanding of fundamental processes and mechanisms. Our continual scientific advancement is hindered only by… (more)

▼ State-of-the-art technology drives scientific progress, pushing the boundaries of our current understanding of fundamental processes and mechanisms. Our continual scientific advancement is hindered only by what we can observe and experimentally verify; thus, it is reasonable to assert that instrument development and improvement is the cornerstone for technological and intellectual growth. For example, the invention of transmission electron microscopy (TEM) allowed us to observe nanoscale phenomena for the first time in the 1930s and even now it is invaluable in the development of smaller, faster electronics. As we uncover more about the fundamentals of nanoscale phenomena, we have realized that images alone reveal only a snapshot of the story; to continue progressing we need a way to observe the entire scene unfold (e.g. how defects affect the flow of current across a transistor or how thermal energy propagates in nanoscale systems like graphene). Recently, by combining the spatial resolution of a TEM with the temporal resolution of ultrafast lasers, ultrafast electron microscopy  or microscope  (UEM) has allowed us to simultaneously observe transient nanoscale phenomena at ultrafast timescales. Ultrafast characterization techniques allow for the investigation of a new realm of previously unseen phenomenon inherent to the transient electronic, magnetic, and structural properties of materials. However, despite the progress made in ultrafast techniques, capturing the nanoscale spatial sub-ns temporal mechanisms and phenomenon at play in magnetic materials (especially during the operation of magnetic devices) has only recently become possible using UEM. With only a handful of instruments available, magnetic characterization using UEM is far from commonplace and any advances made are sparsely reported, and further, specific to the individual instrument. In this dissertation, I outline the development of novel magnetic materials and the establishment of a UEM lab at the University of Minnesota and how I explored the application of it toward the investigation of magnetic materials. In my discussion of UEM, I have made a concerted effort to highlight the unique challenges faced when getting a UEM lab running so that new researchers may circumvent these challenges. Of note in my graduate studies, I assisted in the development of three different magnetic material systems, strained Fe nanoparticles for permanent magnetic applications, FePd for applications in spintronic devices, and a rare-earth transition-metal (RE-TM) alloy that exhibits new magneto-optic phenomena. In studying the morphological and magnetic effects of lasers on these RE-TM alloys using the in situ laser irradiation capabilities of UEM along with standard TEM techniques and computational modeling, I uncovered a possible limitation in their utility for memory applications. Furthermore, with the aid of particle tracing software, I was able to optimize our UEM system for magnetic imaging and demonstrate the resolution of ultrafast demagnetization…

Subjects/Keywords: Electron Microscopy; In situ; Magnetism; Pulsed Laser; Ultrafast

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Schliep, K. (2017). The Investigation Of New Magnetic Materials And Their Phenomena Using Ultrafast Fresnel Transmission Electron Microscopy. (Doctoral Dissertation). University of Minnesota. Retrieved from http://hdl.handle.net/11299/191448

Chicago Manual of Style (16^th Edition):

Schliep, Karl. “The Investigation Of New Magnetic Materials And Their Phenomena Using Ultrafast Fresnel Transmission Electron Microscopy.” 2017. Doctoral Dissertation, University of Minnesota. Accessed April 23, 2021. http://hdl.handle.net/11299/191448.

MLA Handbook (7^th Edition):

Schliep, Karl. “The Investigation Of New Magnetic Materials And Their Phenomena Using Ultrafast Fresnel Transmission Electron Microscopy.” 2017. Web. 23 Apr 2021.

Vancouver:

Schliep K. The Investigation Of New Magnetic Materials And Their Phenomena Using Ultrafast Fresnel Transmission Electron Microscopy. [Internet] [Doctoral dissertation]. University of Minnesota; 2017. [cited 2021 Apr 23]. Available from: http://hdl.handle.net/11299/191448.

Council of Science Editors:

Schliep K. The Investigation Of New Magnetic Materials And Their Phenomena Using Ultrafast Fresnel Transmission Electron Microscopy. [Doctoral Dissertation]. University of Minnesota; 2017. Available from: http://hdl.handle.net/11299/191448

University of Florida

6. Rustagi, Avinash. Optical and Transport Properties of Zero Gap and Finite Gap Semiconductors.

Degree: PhD, Physics, 2016, University of Florida

URL: https://ufdc.ufl.edu/UFE0049874

► A detailed understanding of the electronic, optical and transport properties of semiconductor nanostructures is important in the design and optimization of future novel devices. In… (more)

Subjects/Keywords: Charge carriers; Conceptual lattices; Cyclotron resonance; Electrons; Graphene; Magnetism; Phonons; Pumps; Semiconductors; Velocity; graphene – magneto-optics – noise – semiconductors – terahertz – transport – ultrafast

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Rustagi, A. (2016). Optical and Transport Properties of Zero Gap and Finite Gap Semiconductors. (Doctoral Dissertation). University of Florida. Retrieved from https://ufdc.ufl.edu/UFE0049874

Chicago Manual of Style (16^th Edition):

Rustagi, Avinash. “Optical and Transport Properties of Zero Gap and Finite Gap Semiconductors.” 2016. Doctoral Dissertation, University of Florida. Accessed April 23, 2021. https://ufdc.ufl.edu/UFE0049874.

MLA Handbook (7^th Edition):

Rustagi, Avinash. “Optical and Transport Properties of Zero Gap and Finite Gap Semiconductors.” 2016. Web. 23 Apr 2021.

Vancouver:

Rustagi A. Optical and Transport Properties of Zero Gap and Finite Gap Semiconductors. [Internet] [Doctoral dissertation]. University of Florida; 2016. [cited 2021 Apr 23]. Available from: https://ufdc.ufl.edu/UFE0049874.

Council of Science Editors:

Rustagi A. Optical and Transport Properties of Zero Gap and Finite Gap Semiconductors. [Doctoral Dissertation]. University of Florida; 2016. Available from: https://ufdc.ufl.edu/UFE0049874

7. Panagiotis, Lingos. Ultrafast spin-charge quantum dynamics in strongly correlated systems.

Degree: 2019, University of Crete (UOC); Πανεπιστήμιο Κρήτης

URL: http://hdl.handle.net/10442/hedi/46833

►

In this thesis we investigate the possible role in a non-equilibrium phase transition ofnon-thermal fs dynamics of electronic, magnetic, and lattice coupled degrees of freedomwithin… (more)

▼

In this thesis we investigate the possible role in a non-equilibrium phase transition ofnon-thermal fs dynamics of electronic, magnetic, and lattice coupled degrees of freedomwithin a theoretical framework based on Hubbard operators that treats the magnetic exchange interaction at the microscopic level. We propose a possible mechanism for photoinduced phase transition based on the interplay between a quasi-instantaneous electronic/magnetic pathway and a delayed lattice pathway. In particular, we discuss the possibility that the excitation ofcomposite fermion itinerant quasi-particles dressed by spin fluctuations triggers quasi-instantaneously an insulator to metal and AFM to FM phase transition by providing time-dependent numerical results based on real-space models by solving the quantum kinetic equations of motion. We examine in the role of spin fluctuations driven by photo-carrier populations that interact with a deformable spin and lattice medium. We also discuss the role of the quasi-particle energy bands, modified by fs laser excitation, which arisefrom electron-magnon coupling and the strong Hund’s rule local interaction.

Στη παρούσα εργασία, εξετάζουμε τον πιθανό ρόλο των μη-θερμικών διεργασιών σπιν, φορτίου και πλέγματος, στην επίτευξη υπερταχείας αλλαγής φάσης από μονωτή σε μέταλλο με την βοήθεια φωτοδιέγερσης από laser σε ισχυρώς συσχετιζώμενα συστήματα όπως οι μανγγανίτες. Χρησιμοποιώντας ένα θεωρητικό μοντέλο βασισμένο σε τελεστές Hubbard, περιγράφουμε την μαγνητική αλληλεπίδραση ανταλλαγής σε μικροσκοπικό επίπεδο και λαμβάνοντας υπόψιν τοπικά τις παραμορφώσεις του πλέγματος, παράγουμε τις εξισώσεις κίνησης των σπιν λύνοντας τις στον χρόνο παίρνοντας σαν αποτέλεσμα την δυναμική σπιν-φορτίου σε ατομικά συστήματα πραγματικού χώρου τοπικά. Επίσης παράγουμε την εξίσωση ιδιοτιμών της ενέργειας περιγράφοντας τις ενεργειακές ζώνες μέσω τελεστών “ψευδο-σωματίων” που περιλαμβάνουν διακυμάνσεις σπίν και φορτίου. Εξετάζουμε σε διάφορα μοντέλα την απόκριση των σπίν κατά την διάρκεια φωτοδιέγερσης μέσα σε 100fs και συζητούμε τον πιθανό τους ρόλο στην επίτευξη της μετάβασης φάσης από μονωτή σε μέταλλο και από αντισιδηρομαγνήτη σε σίδηρομαγνήτη. Μέσω τον αριθμητικών υπολογισμών μας δείχνουμε πως διαμορφόνοται τα σπιν σε κάθε άτομο του πλέγματος διακρίνοντας δύο σημαντικά φαινόμενα. Πρώτον είναι η καταστροφή της τάξης του φορτίου στο πλέγμα και δεύτερο η ανάπτυξη ισχυρών διακυμάνσεων σπιν. Εξετάζοντας την δυναμική των ενεργειακών ζωνών δείχνουμε ότι μέσω φωτοδιέγερσης αυτές οι δύο συνθήκες είναι ικανές να προκαλέσουν αύξηση της κινητικής ενέργειας, αλλαγή στα σπιν και στην κατανομή του φορτίου καθώς και χαλάρωση των πλεγματικών παραμορφώσεων με συνέπεια την ρήξη του ενεργειακού χάσματος μέσα σε 100fs. Τα αποτελέσματα μας πιθανών να εξηγούν πειραματικές παρατηρήσεις δημιουργίας φωτοδιεγερμένων μεταβάσεων φάσης σε συστήματα μανγγανιτών.

Subjects/Keywords: Ισχυρώς συσχετισμένα ηλεκτρόνια; Μαγνητισμός και μαγνητικά υλικά; Αλλαγή φάσης; Υπερταχεία δυναμική; Strongly correlated electrons; Femto-magnetism; Phase transitions; Ultrafast dynamic respone

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Panagiotis, L. (2019). Ultrafast spin-charge quantum dynamics in strongly correlated systems. (Thesis). University of Crete (UOC); Πανεπιστήμιο Κρήτης. Retrieved from http://hdl.handle.net/10442/hedi/46833

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Panagiotis, Lingos. “Ultrafast spin-charge quantum dynamics in strongly correlated systems.” 2019. Thesis, University of Crete (UOC); Πανεπιστήμιο Κρήτης. Accessed April 23, 2021. http://hdl.handle.net/10442/hedi/46833.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Panagiotis, Lingos. “Ultrafast spin-charge quantum dynamics in strongly correlated systems.” 2019. Web. 23 Apr 2021.

Vancouver:

Panagiotis L. Ultrafast spin-charge quantum dynamics in strongly correlated systems. [Internet] [Thesis]. University of Crete (UOC); Πανεπιστήμιο Κρήτης; 2019. [cited 2021 Apr 23]. Available from: http://hdl.handle.net/10442/hedi/46833.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Panagiotis L. Ultrafast spin-charge quantum dynamics in strongly correlated systems. [Thesis]. University of Crete (UOC); Πανεπιστήμιο Κρήτης; 2019. Available from: http://hdl.handle.net/10442/hedi/46833

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

8. Hurst, Jerome. Ultrafast spin dynamics in ferromagnetic thin films : Dynamique ultra-rapide de spin dans des films ferromagnétiques.

Degree: Docteur es, Physique de la matière condensée, 2017, Université de Strasbourg

URL: http://www.theses.fr/2017STRAE004

►

Dans cette thèse, on s’intéresse à l'étude théorique et à la simulation numérique de la dynamique de charges et de spins dans des nano-structures métalliques.… (more)

▼

Dans cette thèse, on s’intéresse à l'étude théorique et à la simulation numérique de la dynamique de charges et de spins dans des nano-structures métalliques. Ces dernières années la physique des nano-structures métalliques à connu un intérêt croissant, aussi bien d'un point de vue de la physique fondamental que d'un point de vue des applications technologiques. Il est donc essentiel d'avoir des modèles théoriques nous permettant de décrire correctement ce type d'objets. Cette thèse comporte deux études distinctes. Dans un premier temps on utilise un modèle semi-classique dans l'espace des phases afin d'étudier la dynamique de charges et de spins dans des films ferromagnétiques(Nickel). On décrit dans le même modèle le magnétisme itinérant et le magnétisme localisé. On montre qu'il est possible, en excitant le système avec un laser pulsé femtoseconde dans le domaine du visible, de créer un courant de spin oscillant dans la direction normal du film sur des temps ultrarapides(femtoseconde). Dans un second temps on s’intéresse à la dynamique de charge d'électrons confinés dans des nano-particules d'Or ou bien encore par des potentiels anisotropes. On montre que de telles systèmes sont des candidats intéressant pour faire de la génération d'harmoniques.

In this thesis we focus on the theoritical description and on the numerical simulation of the charge and spin dynamics in metallic nano-structures. The physics of metallic nano-structures has stimulated a huge amount of scientific interest in the last two decades, both for fundamental research and for potential technological applications. The thesis is divided in two parts. In the first part we use a semiclassical phase-space model to study the ultrafast charge and spin dynamics in thin ferromagnetic films (Nickel). Both itinerant and localized magnetism are taken into account. It is shown that an oscillating spin current can be generated in the film via the application of a femtosecond laser pulse in the visible range. In the second part we focus on the charge dynamics of electrons confined in metallic nano-particles (Gold) or anisotropic wells. We show that such systems can be used for high harmonic generation.

Advisors/Committee Members: Hervieux, Paul-Antoine (thesis director), Manfredi, Giovanni (thesis director).

Subjects/Keywords: Dynamique de spin; Magnétisme ultra-rapide; Méthode dans l’espace des phases; Équations de Wigner/Vlasov; Courant de spin; Dynamique non linéaire; Approche variationnelle; Génération d'harmoniques; Spin dynamics; Ultrafast magnetism; Phase-space methods; Wigner/Vlasov equation; Spin current; Nonlinear dynamics; Variational approach; High harmonic generation; 530.4

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Hurst, J. (2017). Ultrafast spin dynamics in ferromagnetic thin films : Dynamique ultra-rapide de spin dans des films ferromagnétiques. (Doctoral Dissertation). Université de Strasbourg. Retrieved from http://www.theses.fr/2017STRAE004

Chicago Manual of Style (16^th Edition):

Hurst, Jerome. “Ultrafast spin dynamics in ferromagnetic thin films : Dynamique ultra-rapide de spin dans des films ferromagnétiques.” 2017. Doctoral Dissertation, Université de Strasbourg. Accessed April 23, 2021. http://www.theses.fr/2017STRAE004.

MLA Handbook (7^th Edition):

Hurst, Jerome. “Ultrafast spin dynamics in ferromagnetic thin films : Dynamique ultra-rapide de spin dans des films ferromagnétiques.” 2017. Web. 23 Apr 2021.

Vancouver:

Hurst J. Ultrafast spin dynamics in ferromagnetic thin films : Dynamique ultra-rapide de spin dans des films ferromagnétiques. [Internet] [Doctoral dissertation]. Université de Strasbourg; 2017. [cited 2021 Apr 23]. Available from: http://www.theses.fr/2017STRAE004.

Council of Science Editors:

Hurst J. Ultrafast spin dynamics in ferromagnetic thin films : Dynamique ultra-rapide de spin dans des films ferromagnétiques. [Doctoral Dissertation]. Université de Strasbourg; 2017. Available from: http://www.theses.fr/2017STRAE004

9. Patz, Aaron E. Ultrafast laser dynamics and interactions in complex materials.

Degree: 2017, Iowa State University

URL: https://lib.dr.iastate.edu/etd/15395

► The work described in this thesis underscores specific examples of using an ultrafast laser as a materials research tool for studying condensed matter physics in… (more)

Subjects/Keywords: BaFe2As2; GaMnAs; Laser; Magnetism; Superconductor; Ultrafast; Condensed Matter Physics; Materials Science and Engineering; Mechanics of Materials

…the low-power ultrafast magneto-optical and differential reflecitivity setup… …polarimetry technique measures the ellipticity η . . . . . 50 Figure 3.6 Ultrafast photoinduced… …Figure 3.7 Ultrafast photoinduced dynamics of the nematic order parameter in (under-doped… …Experimental method used for measuring ultrafast differential reflectivity 58 Figure 4.2… …normalized to normal state spectra at 20K. (d) Ultrafast THz pump probe scan for…

11 more images…

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Patz, A. E. (2017). Ultrafast laser dynamics and interactions in complex materials. (Thesis). Iowa State University. Retrieved from https://lib.dr.iastate.edu/etd/15395

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Patz, Aaron E. “Ultrafast laser dynamics and interactions in complex materials.” 2017. Thesis, Iowa State University. Accessed April 23, 2021. https://lib.dr.iastate.edu/etd/15395.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Patz, Aaron E. “Ultrafast laser dynamics and interactions in complex materials.” 2017. Web. 23 Apr 2021.

Vancouver:

Patz AE. Ultrafast laser dynamics and interactions in complex materials. [Internet] [Thesis]. Iowa State University; 2017. [cited 2021 Apr 23]. Available from: https://lib.dr.iastate.edu/etd/15395.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Patz AE. Ultrafast laser dynamics and interactions in complex materials. [Thesis]. Iowa State University; 2017. Available from: https://lib.dr.iastate.edu/etd/15395

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Florida

10. Wang, Xiaoming. Ultrafast Optical Spectroscopic Study of Semiconductors in High Magnetic Fields.

Degree: PhD, Physics, 2008, University of Florida

URL: https://ufdc.ufl.edu/UFE0019805

► We studied the magneto-excitonic states of two-dimensional (2D) electron and hole gas in InxGa1-xAs/GaAs multiple quantum wells (MQW) with continuous wave (CW) optical spectroscopic methods,… (more)

▼ We studied the magneto-excitonic states of two-dimensional (2D) electron and hole gas in InxGa1-xAs/GaAs multiple quantum wells (MQW) with continuous wave (CW) optical spectroscopic methods, including transmission and photoluminescence spectroscopy, in high magnetic field up to 30 Tesla. Interband Landau level (LL) transitions are clearly identified. The anticrossing behavior in the Landau fan diagram of the transmission spectrum is interpreted as dark and bright exciton mixing due to Coulomb interaction. With the unique facility of ultrafast optics at National High Magnetic Field Laboratory, we are able to change the 2D electron hole gas into 0D and increase density of each quantum state as well as the actual sheet carrier density in the quantum well (up to 1012cm-2) dramatically. Under these conditions, interactions between electron and hole pairs confined in 0D system play a very important role in the electron hole recombination process. With high power pulsed lasers and cryogenic equipment, we studied the strong magneto photoluminescence emission from InxGa1-xAs/GaAs MQW in high magnetic field. By analyzing the power dependent, field dependent and direction dependent PL spectrum, the abnormally strong PL emission from InxGa1-xAs/GaAs MQW in high magnetic field is found to be the result of cooperative recombination of high density magneto electron-hole plasmas. This abnormally strong photoluminescence from InxGa1-xAs/GaAs MQW in high magnetic field under CPA excitation is proved to be superfluorescence. We studied CW spectroscopic properties of ZnO semiconductors including reflectivity and photoluminescence at different crystal orientations. A, B excitonic states in ZnO semiconductors are clearly identified. Also, with time resolved pump probe spectroscopy, we studied the carrier dynamics of excitonic states of A and B in bulk ZnO as well as ZnO epilayer and nanorods. ( en ) Advisors/Committee Members: Reitze, David H. (committee chair), Stanton, Christopher J. (committee member), Rinzler, Andrew G. (committee member), Tanner, David B. (committee member), Kleiman, Valeria D. (committee member).

Subjects/Keywords: Atoms; Charge carriers; Electrons; Excitons; Lasers; Magnetic fields; Magnetism; Magnets; Quantum wells; Semiconductors; exciton, magnetooptics, quantumwell, semiconductor, superfluorescence, ultrafast

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Wang, X. (2008). Ultrafast Optical Spectroscopic Study of Semiconductors in High Magnetic Fields. (Doctoral Dissertation). University of Florida. Retrieved from https://ufdc.ufl.edu/UFE0019805

Chicago Manual of Style (16^th Edition):

Wang, Xiaoming. “Ultrafast Optical Spectroscopic Study of Semiconductors in High Magnetic Fields.” 2008. Doctoral Dissertation, University of Florida. Accessed April 23, 2021. https://ufdc.ufl.edu/UFE0019805.

MLA Handbook (7^th Edition):

Wang, Xiaoming. “Ultrafast Optical Spectroscopic Study of Semiconductors in High Magnetic Fields.” 2008. Web. 23 Apr 2021.

Vancouver:

Wang X. Ultrafast Optical Spectroscopic Study of Semiconductors in High Magnetic Fields. [Internet] [Doctoral dissertation]. University of Florida; 2008. [cited 2021 Apr 23]. Available from: https://ufdc.ufl.edu/UFE0019805.

Council of Science Editors:

Wang X. Ultrafast Optical Spectroscopic Study of Semiconductors in High Magnetic Fields. [Doctoral Dissertation]. University of Florida; 2008. Available from: https://ufdc.ufl.edu/UFE0019805

Université de Lorraine

11. Scheid, Philippe. Investigation of light–induced ultrafast magnetization dynamics using ab initio methods : Étude de la dynamique ultrarapide de l’aimantation induite par la lumière selon des méthodes ab initio.

Degree: Docteur es, Physique, 2020, Université de Lorraine

URL: http://www.theses.fr/2020LORR0166

►

Cette thèse commence par une revue de l’état actuel de l’expérimentation et de la théorie liées à la désaimantation ultrarapide induite par de la lumière,… (more)

▼

Cette thèse commence par une revue de l’état actuel de l’expérimentation et de la théorie liées à la désaimantation ultrarapide induite par de la lumière, ainsi qu'au retournement tout optique dépendant de l'hélicité. Ceci est suivi d’un aperçu de la théorie de la fonctionnelle de la densité, sur laquelle repose la plupart des travaux rapportés par la suite. La première partie des résultats concerne l’étude de l’effet d’une élévation de la température électronique sur les propriétés de la matière aimantée, et plus précisément Ni, Co, Fe et FePt. Nous montrons que le moment magnétique de chaque atome disparaı̂t à la température de Stoner, et que, de manière plus générale ce phénomène impacte l’énergie électronique et la chaleur spécifique, même à basse température électronique. Ensuite, nous montrons que lors d’une augmentation de la température électronique, l’échange interatomique d’Heisenberg, responsable de l’ordre magnétique, diminue. En utilisant l’équation de Landau–Lifshitz–Gilbert atomistique, nous démontrons que cette diminution est suffisante pour induire une forte réduction de l’aimantation moyenne en créant des excitations transversales. La deuxième partie des résultats concerne l’origine de la dépendante en l’hélicité de la dynamique induite par la lumière. Alors que la littérature l’attribue principalement à l’effet Faraday inverse, nous soutenons qu’un autre phénomène, se produisant lors de l’absorption de la lumière, peut rendre compte de la dynamique expérimentale. En effet, lorsque la lumière est absorbée et que les électrons sont excités, le couplage spin–orbite permet la modification de l’état de spin. Il en résulte un changement de la valeur des moments magnétiques atomiques, persistant même après la disparition de la lumière, par opposition à l’effet Faraday inverse. Ensuite, en utilisant la théorie de la fonctionnelle de la densité dépendante du temps, nous calculons la dynamique de l’aimantation induite par de véritables impulsions femtosecondes polarisées circulairement dans le domaine optique et XUV. Dans les deux cas, la dynamique est dépendante de l’hélicité. Cette caractéristique est largement amplifiée dans le régime XUV impliquant les états de semi–coeur 3p. Enfin, nous comparons le rôle relatif de l’effet Faraday inverse et de l’aimantation induite lors de l’absorption de la lumière et montrons que cette dernière joue un rôle prépondérant, surtout après la disparition de la lumière et en régime XUV.

This thesis begins with a review of the current experimental and theoretical state of the art related to the light-induced ultrafast demagnetization and the all-optical helicity-dependent switching. This is followed by an overview of density functional theory, upon which relies most of the work reported thereafter. The first set of results concerns the ab initio study of the effect of a rise in the electronic temperature on the magnetized matter properties, and more specifically Fe, Co, Ni and FePt. We show that the magnetic moment carried by each atom disappears at the so–called Stoner…

Advisors/Committee Members: Lebègue, Sébastien (thesis director), Malinowski, Grégory (thesis director).

Subjects/Keywords: Magnétisme; Ab initio; Théorie de la fonctionnelle de la densité; Théorie de la fonctionnelle de la densité dépendante du temps; Désaimantation ultrarapide; Retournement tout-optique; Magnetism; Ab initio; Density functional theory; Time-dependent density functional theory; Ultrafast demagnetization; All-optical switching; 538.3

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Scheid, P. (2020). Investigation of light–induced ultrafast magnetization dynamics using ab initio methods : Étude de la dynamique ultrarapide de l’aimantation induite par la lumière selon des méthodes ab initio. (Doctoral Dissertation). Université de Lorraine. Retrieved from http://www.theses.fr/2020LORR0166

Chicago Manual of Style (16^th Edition):

Scheid, Philippe. “Investigation of light–induced ultrafast magnetization dynamics using ab initio methods : Étude de la dynamique ultrarapide de l’aimantation induite par la lumière selon des méthodes ab initio.” 2020. Doctoral Dissertation, Université de Lorraine. Accessed April 23, 2021. http://www.theses.fr/2020LORR0166.

MLA Handbook (7^th Edition):

Scheid, Philippe. “Investigation of light–induced ultrafast magnetization dynamics using ab initio methods : Étude de la dynamique ultrarapide de l’aimantation induite par la lumière selon des méthodes ab initio.” 2020. Web. 23 Apr 2021.

Vancouver:

Scheid P. Investigation of light–induced ultrafast magnetization dynamics using ab initio methods : Étude de la dynamique ultrarapide de l’aimantation induite par la lumière selon des méthodes ab initio. [Internet] [Doctoral dissertation]. Université de Lorraine; 2020. [cited 2021 Apr 23]. Available from: http://www.theses.fr/2020LORR0166.

Council of Science Editors:

Scheid P. Investigation of light–induced ultrafast magnetization dynamics using ab initio methods : Étude de la dynamique ultrarapide de l’aimantation induite par la lumière selon des méthodes ab initio. [Doctoral Dissertation]. Université de Lorraine; 2020. Available from: http://www.theses.fr/2020LORR0166

12. 佐藤,哲也. フェリ磁性GdFeCo多層薄膜の超短パルス光照射による極短時間加熱ならびにエネルギー散逸過程に関する研究 : Research of Ultrashort Pulsed Light-induced Ultrafast Thermalization and Energy Dissipation Process in Ferrimagnetic GdFeCo Multi-layered Thin Films.

Degree: 博士（工学）, 2015, Nihon University / 日本大学

URL: http://repository.nihon-u.ac.jp/xmlui/handle/11263/489 ; http://dx.doi.org/10.15006/32665A4883

Subjects/Keywords: 磁性; Magnetism; 熱アシスト磁気記録; Heat-Assisted Magnetic Recording; 超高速磁化ダイナミクス; Ultrafast Magnetization Dynamics; 全光ポンプ・プローブ法; All-Optical Pump-Probe Method; 希土類遷移金属; Rare-Earth Transition-Metal

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

佐藤,哲也. (2015). フェリ磁性GdFeCo多層薄膜の超短パルス光照射による極短時間加熱ならびにエネルギー散逸過程に関する研究 : Research of Ultrashort Pulsed Light-induced Ultrafast Thermalization and Energy Dissipation Process in Ferrimagnetic GdFeCo Multi-layered Thin Films. (Thesis). Nihon University / 日本大学. Retrieved from http://repository.nihon-u.ac.jp/xmlui/handle/11263/489 ; http://dx.doi.org/10.15006/32665A4883

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

佐藤,哲也. “フェリ磁性GdFeCo多層薄膜の超短パルス光照射による極短時間加熱ならびにエネルギー散逸過程に関する研究 : Research of Ultrashort Pulsed Light-induced Ultrafast Thermalization and Energy Dissipation Process in Ferrimagnetic GdFeCo Multi-layered Thin Films.” 2015. Thesis, Nihon University / 日本大学. Accessed April 23, 2021. http://repository.nihon-u.ac.jp/xmlui/handle/11263/489 ; http://dx.doi.org/10.15006/32665A4883.

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

佐藤,哲也. “フェリ磁性GdFeCo多層薄膜の超短パルス光照射による極短時間加熱ならびにエネルギー散逸過程に関する研究 : Research of Ultrashort Pulsed Light-induced Ultrafast Thermalization and Energy Dissipation Process in Ferrimagnetic GdFeCo Multi-layered Thin Films.” 2015. Web. 23 Apr 2021.

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete

Vancouver:

佐藤,哲也. フェリ磁性GdFeCo多層薄膜の超短パルス光照射による極短時間加熱ならびにエネルギー散逸過程に関する研究 : Research of Ultrashort Pulsed Light-induced Ultrafast Thermalization and Energy Dissipation Process in Ferrimagnetic GdFeCo Multi-layered Thin Films. [Internet] [Thesis]. Nihon University / 日本大学; 2015. [cited 2021 Apr 23]. Available from: http://repository.nihon-u.ac.jp/xmlui/handle/11263/489 ; http://dx.doi.org/10.15006/32665A4883.

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

佐藤,哲也. フェリ磁性GdFeCo多層薄膜の超短パルス光照射による極短時間加熱ならびにエネルギー散逸過程に関する研究 : Research of Ultrashort Pulsed Light-induced Ultrafast Thermalization and Energy Dissipation Process in Ferrimagnetic GdFeCo Multi-layered Thin Films. [Thesis]. Nihon University / 日本大学; 2015. Available from: http://repository.nihon-u.ac.jp/xmlui/handle/11263/489 ; http://dx.doi.org/10.15006/32665A4883

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Not specified: Masters Thesis or Doctoral Dissertation

Open Access Theses and Dissertations