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You searched for subject:( Heisenberg Langevin). Showing records 1 – 2 of 2 total matches.

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1. Malek Akhlagh, Mohammad Moein. Heisenberg-Langevin Formalism for Open Circuit-QED Systems .

Degree: PhD, 2017, Princeton University

We present a Heisenberg-Langevin formalism to study the effective dynamics of a superconducting qubit coupled to an open multimode resonator, without resorting to the rotating wave, two level, Born or Markov approximations. Our effective equations are derived by eliminating resonator degrees of freedom while encoding their effect in the Green's function of the electromagnetic background. We account for the openness of the resonator exactly by employing a spectral representation for the Green's function in terms of a set of non-Hermitian modes. A well-behaved time domain perturbation theory is derived to systematically account for the nonlinearity of weakly nonlinear qubits like transmon. We apply this method to the problem of spontaneous emission, capturing accurately the non-Markovian features of the qubit dynamics, valid for any qubit-resonator coupling strength. Any discrete-level quantum system coupled to the electromagnetic continuum is subject to radiative decay and renormalization of its energy levels. When inside a cavity, these quantities can be strongly modified with respect to vacuum. Generally, this modification can be captured by including only the closest resonant cavity mode. In circuit QED architecture, with substantial coupling strengths, it is however found that such rates are strongly influenced by far off-resonant modes. A multimode calculation over the infinite set of cavity modes leads to divergences unless an artificial cutoff is imposed. Previous studies have not pointed out what the source of this divergence is. Quite interestingly, the renormalization of spectrum is mutual, i.e. the electromagnetic modal structure of the cavity is also modified due to scattering by the atom. In cavity QED, this phenomenon is manifested as a diamagnetic term, known as the A2 contribution. We show that unless the effect of A2 is accounted for up to all orders exactly, any multimode calculations of circuit QED quantities is bound to diverge. Subsequently, we present the calculation of finite radiative corrections to qubit properties that is free of an artificially introduced high frequency cut-off. Advisors/Committee Members: Tureci, Hakan E (advisor).

Subjects/Keywords: Cavity-QED; Circuit-QED; Heisenberg-Langevin; Lamb Shift; Quantum Optics; Spontaneous Emission

…Lamb shift using our Heisenberg-Langevin framework. The transmission |T |2 is shown versus… …Heisenberg-Langevin formalism, which does not employ rotating wave, two-level, Born or Markov… …137 A.2.2 Classical Hamiltonian and Heisenberg equations of motion in the continuum limit… …transmon via a Heisenberg picture Green’s function method 149 C.1 Definition of G(x, t|x0… 

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

APA (6th Edition):

Malek Akhlagh, M. M. (2017). Heisenberg-Langevin Formalism for Open Circuit-QED Systems . (Doctoral Dissertation). Princeton University. Retrieved from http://arks.princeton.edu/ark:/88435/dsp01ff3657916

Chicago Manual of Style (16th Edition):

Malek Akhlagh, Mohammad Moein. “Heisenberg-Langevin Formalism for Open Circuit-QED Systems .” 2017. Doctoral Dissertation, Princeton University. Accessed December 05, 2020. http://arks.princeton.edu/ark:/88435/dsp01ff3657916.

MLA Handbook (7th Edition):

Malek Akhlagh, Mohammad Moein. “Heisenberg-Langevin Formalism for Open Circuit-QED Systems .” 2017. Web. 05 Dec 2020.

Vancouver:

Malek Akhlagh MM. Heisenberg-Langevin Formalism for Open Circuit-QED Systems . [Internet] [Doctoral dissertation]. Princeton University; 2017. [cited 2020 Dec 05]. Available from: http://arks.princeton.edu/ark:/88435/dsp01ff3657916.

Council of Science Editors:

Malek Akhlagh MM. Heisenberg-Langevin Formalism for Open Circuit-QED Systems . [Doctoral Dissertation]. Princeton University; 2017. Available from: http://arks.princeton.edu/ark:/88435/dsp01ff3657916

2. Alzar, Carlos Leonardo Garrido. Estudo de propriedades quânticas dos feixes sonda e de bombeio na transparência induzida por laser.

Degree: PhD, Física, 2002, University of São Paulo

Este trabalho apresenta uma contribuição ao estudo das flutuações quânticas dos feixes sonda e de bombeio na condição de transparência induzida por laser. Com esse estudo conseguimos observar nas flutuações dos campos uma manifestação do caráter coerente da interação dos átomos com os feixes. Para alcançar nosso objetivo, derivamos a teoria do fenômeno da transparência induzida tratando ambos feixes dentro do formalismo quântico. Com tal formulação, encontramos que a condição de transparência induzida corresponde a um estado de equilíbrio dinâmico do sistema átomo - campo de bombeio - campo sonda onde, os átomos redistribuem os fótons entre os campos, correlacionando os mesmos e alterando, ao mesmo tempo, as propriedades estatísticas desses feixes. Utilizando dois critérios diferentes, mostrando que a correlação entre os feixes sonda e de bombeio é de natureza quântica, o que possibilita a aplicação desse sistema, por exemplo, na informação e computação quânticas. Os resultados experimentais obtidos confirmaram as previsões teóricas em relação às flutuações quânticas dos campos, e a existência de uma correlação entre eles. Trata-se da primeira investigação experimental de propriedades estatísticas dos campos em transparência induzida. A correlação de intensidade medida é o primeiro passo para a observação de emaranhamento entre feixes sonda e de bombeio na condiçào de transparência induzida.

In this work we presente a contribution to the study of quantum fluctuations of pump and probe filds in the Electromagnetically Induced Transparency (EIT) condition. We observed in the fields fluctuations evidence of the coherent character of the interaction between the atoms and the fields. To reach our purpose, the fields were treated quantum-mechanically in deriving the theory of the EIT phenomenon. Using this formulation, we concluded that the EIT condition corresponds to a state of dynamical equilibrium of the system atom pump field probe field, where the atoms redistribute the photons between both fields, correlating them and, at the same time, affecting their statistical properties. By means of two different criteria we showed that such a correlation is of quantum nature, making possible the application of this system in, for example, quantum information and quantum computation. The theoretical predictions were corroborated by our experimental results regarding the quantum fluctuations and the existence of a correlation between the pump and probe fields. This is the first experiment to investigate statistical properties of the fields in EIT. The intensity correlation measured is the first step towards the observation of entanglement between the fields.

Advisors/Committee Members: Nussenzveig, Paulo Alberto.

Subjects/Keywords: Effects in coherent atomic media; Effects in coherent atomic media; Heisenberg-langevin equations; Heisenberg-langevin equations; Quantum correlations; Quantum correlations; Quantum fluctuations of the electromagnetic field; Quantum fluctuations of the electromagnetic field; Transparency laser induced; Transparency laser induced

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

APA (6th Edition):

Alzar, C. L. G. (2002). Estudo de propriedades quânticas dos feixes sonda e de bombeio na transparência induzida por laser. (Doctoral Dissertation). University of São Paulo. Retrieved from http://www.teses.usp.br/teses/disponiveis/43/43134/tde-11122013-173616/ ;

Chicago Manual of Style (16th Edition):

Alzar, Carlos Leonardo Garrido. “Estudo de propriedades quânticas dos feixes sonda e de bombeio na transparência induzida por laser.” 2002. Doctoral Dissertation, University of São Paulo. Accessed December 05, 2020. http://www.teses.usp.br/teses/disponiveis/43/43134/tde-11122013-173616/ ;.

MLA Handbook (7th Edition):

Alzar, Carlos Leonardo Garrido. “Estudo de propriedades quânticas dos feixes sonda e de bombeio na transparência induzida por laser.” 2002. Web. 05 Dec 2020.

Vancouver:

Alzar CLG. Estudo de propriedades quânticas dos feixes sonda e de bombeio na transparência induzida por laser. [Internet] [Doctoral dissertation]. University of São Paulo; 2002. [cited 2020 Dec 05]. Available from: http://www.teses.usp.br/teses/disponiveis/43/43134/tde-11122013-173616/ ;.

Council of Science Editors:

Alzar CLG. Estudo de propriedades quânticas dos feixes sonda e de bombeio na transparência induzida por laser. [Doctoral Dissertation]. University of São Paulo; 2002. Available from: http://www.teses.usp.br/teses/disponiveis/43/43134/tde-11122013-173616/ ;

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