Quantum driven dissipative parametric oscillator in a blackbody radiation field

Abstract

We consider the general open system problem of a charged quantum oscillator confined in a harmonic trap, whose frequency can be arbitrarily modulated in time, that interacts with both an incoherent quantized (blackbody) radiation field and with an arbitrary coherent laser field. We assume that the oscillator is initially in thermodynamic equilibrium with its environment, a nonfactorized initial density matrix of the system and the environment, and that at t = 0 the modulation of the frequency, the coupling to the incoherent and the coherent radiation are switched on. The subsequent dynamics, induced by the presence of the blackbody radiation, the laser field and the frequency modulation, is studied in the framework of the influence functional approach. This approach allows incorporating, in analytic closed formulae, the non-Markovian character of the oscillator-environment interaction at any temperature as well the non-Markovian character of the blackbody radiation and its zero-point fluctuations. Expressions for the time evolution of the covariance matrix elements of the quantum fluctuations and the reduced density-operator are obtained.

Quantum limit for driven linear non-Markovian open-quantum-systems

“…Thus, it is possible that the initial correlations are not available to the experimentalist [29]. Although initial conditions may be relevant in the generation of new control strategies in open quantum systems [33][34][35][36], they are not considered below for the sake of concreteness. According to the influence functional approach, at time t the matrix elements…”

“…Thus, the case of purely Ohmic dissipation is referred to as Markovian dynamics whereas the case of Ohmic dissipation with a finite cut-off frequency is understood to account for non-Markovian dynamics. Further details on the power noise and its relation to the non-Markovian character of the dynamics can be found in [8,36].…”

Open system perspective on incoherent excitation of light-harvesting systems

“…This is distinctly different from the results of pulsed laser excitation, as most recently shown for coherent vs. incoherent excitation with the same spectrum [6]. Thus, the coherent pulsed laser experiments provide important insight into the nature of the system Hamiltonian and of the coupling of the system to the environment, but describe coherences in dynamics that is dramatically different than natural processes [4,5,[7][8][9][10][11][12][13][14][15].…”

“…Given the significance of the incoherent excitation process, and the difficulty of doing experiments with incoherent light, theoretical/computational studies become increasingly important. As a result, a number of such computations have been carried out [3,4,10,11,14], and insight into dynamics induced by incoherent radiation have been obtained. However, a number of significant issues, addressed in this paper, have not been explored.…”

On oscillator–bath system: exact propagator, reduced density matrix and Greenʼs function

“…The dynamics of an open quantum system can be described in terms of generalized master equations [18,19] and Langevin equations [20,21] and due to the complexity of correctly incorporating different physical parameters, various approximations such as weak-coupling regime, Markovian limit, high temperature, or the initial factorizing condition are usually invoked. This approximations are not valid for open quantum systems in the low temperature regime or in the presence of initial correlations between the system and its environment or in the case of driven non-equilibrium quantum systems [22].…”