Effect of high frequency modes of medium on an open quantum system

We present a method to calculate the real time effective propagator of a generic open quantum system, immersed in a medium using a wave function based framework. The medium is characterized by a set of harmonic oscillators having a continuous span of frequencies. This technique has been applied to the Caldeira–Leggett model showing that high frequency modes of the medium do not contribute towards decay of the population of states of the open system. In fact, they cause a Rabi-type oscillation. Moreover, our wave function based approach provides an excellent alternative to conventional formalisms involving the density matrix.

Download Full-text

Open quantum system of two coupled harmonic oscillators for application in deep inelastic heavy ion collisions

Journal of Physics A General Physics ◽

10.1088/0305-4470/20/8/026 ◽

1987 ◽

Vol 20 (8) ◽

pp. 2121-2131 ◽

Cited By ~ 58

Author(s):

A Sandulescu ◽

H Scutaru ◽

W Scheid

Keyword(s):

Quantum System ◽

Heavy Ion Collisions ◽

Open Quantum System ◽

Heavy Ion ◽

Harmonic Oscillators ◽

Coupled Harmonic Oscillators ◽

Open Quantum ◽

Ion Collisions

Download Full-text

Wigner function of open quantum system

Infinite Dimensional Analysis Quantum Probability and Related Topics ◽

10.1142/s0219025718500261 ◽

2018 ◽

Vol 21 (04) ◽

pp. 1850026

Author(s):

Maxim O. Burkatckii

Keyword(s):

Phase Space ◽

Quantum System ◽

Wigner Function ◽

Open System ◽

Open Quantum System ◽

Open Quantum

We consider a quantum system consisting of two subsystems (open system and environment). We have proved that the Wigner function of an open system is the integral of the Wigner function of a larger system with respect to coordinates of the phase space of the classical subsystem corresponding to the entourage.

Download Full-text

Specific heat and thermal entanglement in an open quantum system

Modern Physics Letters A ◽

10.1142/s0217732319500597 ◽

2019 ◽

Vol 34 (11) ◽

pp. 1950059 ◽

Cited By ~ 2

Author(s):

B. Lari ◽

H. Hassanabadi

Keyword(s):

Density Matrix ◽

Specific Heat ◽

Quantum System ◽

Quantum Entanglement ◽

Open Quantum System ◽

Time Behavior ◽

Coupling Constant ◽

Thermal Entanglement ◽

Open Quantum ◽

Xxz Chain

In this paper, the density matrix is obtained using the non-Markovian master equation method for a system consisting of two-qubit modeling with the Heisenberg XXZ chain, which involves the Dzyaloshinskii–Moriya interaction and is exposed to the bosonic baths. Also, using the proposed formula for calculating the specific heat through the density matrix of the open quantum system, the specific heat is calculated. The quantum entanglement behavior with time and coupling constant is investigated. It is observed that the specific heat at low temperatures becomes negative when the system is exposed to the environment. The time behavior of quantum entanglement for this model showed that the entanglement decreases to zero with increasing time.

Download Full-text

On the connection between microscopic description and memory effects in open quantum system dynamics

Quantum ◽

10.22331/q-2021-04-26-439 ◽

2021 ◽

Vol 5 ◽

pp. 439

Author(s):

Andrea Smirne ◽

Nina Megier ◽

Bassano Vacchini

Keyword(s):

System Dynamics ◽

Quantum System ◽

Open System ◽

Open Quantum System ◽

Memory Effects ◽

Initial State ◽

System Environment ◽

Open Quantum ◽

Microscopic Models ◽

Environment Evolution

The exchange of information between an open quantum system and its environment allows us to discriminate among different kinds of dynamics, in particular detecting memory effects to characterize non-Markovianity. Here, we investigate the role played by the system-environment correlations and the environmental evolution in the flow of information. First, we derive general conditions ensuring that two generalized dephasing microscopic models of the global system-environment evolution result exactly in the same open-system dynamics, for any initial state of the system. Then, we use the trace distance to quantify the distinct contributions to the information inside and outside the open system in the two models. Our analysis clarifies how the interplay between system-environment correlations and environmental-state distinguishability can lead to the same information flow from and toward the open system, despite significant qualitative and quantitative differences at the level of the global evolution.

Download Full-text