Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Laser Physics

Non-markovian relaxation of a three-level atom in two laser fields with noise

Vitalii Semin

Published Jan 13, 2020• 3 citations
Publisher

Abstract

Abstract Non-markovian relaxation of a three-level system is considered with the help of the generalized stochastic Schrödinger equation. The main advantage of the approach is ensuring of complete positivity of the density operator of a system that is quite difficult to achieve by other approaches. The direct computer simulation of the dynamics of a three-level system shows a noticeable effect of non-markovianity on the dynamical parameters.

DOI
10.1088/1555-6611/ab65c3

Related papers

Stochastic Non-Markovian Schroedinger equation for a three-level quantum system

Vitalii Semin, Andrei Pavelev

Non-Markovian dynamics of a three-level system is studied with the help of stochastic Schrodinger equation (SSE). We derive a new form of SSE for a three-level system driven by four independent Ornstein-Uhlenbeck stochastic noises. The main advantage of the suggested SSE is the ensuring of the complete positivity of the reduced density operator. We demonstrate significant influence of the non-Markovian noises on the dynamics of the three-level quantum system.

International Conference on Information Technology and Nanotechnology (ITNT)•Jan 1, 2017•1 citation

Non-Markovian generalization of a stochastic Schrödinger equation for two interacting qubits

Vitalii Semin

The non-Markovian generalization of a stochastic Schrödinger equation of diffusion type is considered. Generalization is performed by adding to the system Hamiltonian new stochastic terms some of which are correlated with the environment. The advantage of such an approach is ensuring the complete positivity of the density operator at any time. We illustrate the approach by the example of two interacting qubits in noisy laser fields.

Europhysics Letters (EPL)•Apr 30, 2020•1 citation

Two-level system immersed in a photonic band-gap material: A non-Markovian stochastic Schrödinger-equation approach

Inés de Vega, Daniel Alonso, Pierre Gaspard

It is our aim to study the dynamics of a two-level atom immersed in the modified radiation field of a photonic band-gap material using non-Markovian stochastic Schr\"odinger equations. Up to now, such methodology has only been applied to toy models and not to physically realistic systems as the one presented here. In order to check its validity, we shall study several of the physical phenomena already described in the literature within non-Markovian master equations, such as the long-time-limit residual population in the excited level of the atom and the population inversion which occurs in the atomic system when applying an external laser field. In addition to the stochastic equation, we propose a non-Markovian master equation derived from the stochastic formalism, which in contrast to the current models of master equation preserves positivity. We propose a correlation function for the radiation field (environment) that captures many of the physically relevant aspects of the problem and describes the short-time behavior in a more accurate way than previously proposed ones. This characteristic permits a correct description of the fluctuations of the electromagnetic field, which in the stochastic formalism are represented by the noise, and a better description of the non-Markovian effects in the atomic dynamics. The methodology presented in this paper to apply stochastic Schr\"odinger equations can be followed to study more complex systems, like many-level atoms embedded in more complicated photonic band-gap structures.

Physical Review A•Feb 24, 2005•63 citations

Simulation of non-Markovian dynamics of dipole-dipole interacting atoms

Vitalii Semin, Andrei Pavelev

We investigate non-markovian dynamics of two interacting two-level systems by numerical solution of the stochastic Schroedinger equation (SSE). It is shown that non- markovian noises have significant influence on dynamics of atomic levels populations.

Journal of Physics Conference Series•Dec 1, 2018•1 citation

Non-Markovian Relaxation of a Three-Level System: Quantum Trajectory Approach

Jun Jing, Ting Yu

The non-Markovian dynamics of a three-level quantum system coupled to a bosonic environment is a difficult problem due to the lack of an exact dynamic equation such as a master equation. We present for the first time an exact quantum trajectory approach to a dissipative three-level model. We have established a convolutionless stochastic Schrödinger equation called the time-local quantum state diffusion (QSD) equation without any approximations, in particular, without Markov approximation. Our exact time-local QSD equation opens a new avenue for exploring quantum dynamics for a higher dimensional quantum system coupled to a non-Markovian environment.

arXiv:1009.5301•Physical Review Letters•Dec 8, 2010•136 citations

Qubit dynamics in an external laser field

D.M. Vasilev, Vitalii Semin

In this paper, dynamics of a qubit in an external laser field is investigated for the non-Markov environment described by an Ornstein-Uhlenbeck process. A non-linear non-Markovian stochastic Schrödinger equation is derived for the quantum system. The stochastic equation is preserved for a positive semi-definite of the density matrix and its trace. By the numerical solution of the equation, the probability of finding the system in the excited state and the influence of non-Markov noise parameters on this probability are studie.

Computer Optics•Aug 1, 2019•1 citation
Abstract Non-markovian relaxation of a three-level system is considered with the help of the generalized stochastic Schrödinger equation. The main advantage of the approach is ensuring of complete positivity of the density operator of a system that is quite difficult to achieve by other approaches. The direct computer simulation of the dynamics of a three-level system shows a noticeable effect of non-markovianity on the dynamical parameters.
It is our aim to study the dynamics of a two-level atom immersed in the modified radiation field of a photonic band-gap material using non-Markovian stochastic Schr\"odinger equations. Up to now, such methodology has only been applied to toy models and not to physically realistic systems as the one presented here. In order to check its validity, we shall study several of the physical phenomena already described in the literature within non-Markovian master equations, such as the long-time-limit residual population in the excited level of the atom and the population inversion which occurs in the atomic system when applying an external laser field. In addition to the stochastic equation, we propose a non-Markovian master equation derived from the stochastic formalism, which in contrast to the current models of master equation preserves positivity. We propose a correlation function for the radiation field (environment) that captures many of the physically relevant aspects of the problem and describes the short-time behavior in a more accurate way than previously proposed ones. This characteristic permits a correct description of the fluctuations of the electromagnetic field, which in the stochastic formalism are represented by the noise, and a better description of the non-Markovian effects in the atomic dynamics. The methodology presented in this paper to apply stochastic Schr\"odinger equations can be followed to study more complex systems, like many-level atoms embedded in more complicated photonic band-gap structures.
The non-Markovian dynamics of a three-level quantum system coupled to a bosonic environment is a difficult problem due to the lack of an exact dynamic equation such as a master equation. We present for the first time an exact quantum trajectory approach to a dissipative three-level model. We have established a convolutionless stochastic Schrödinger equation called the time-local quantum state diffusion (QSD) equation without any approximations, in particular, without Markov approximation. Our exact time-local QSD equation opens a new avenue for exploring quantum dynamics for a higher dimensional quantum system coupled to a non-Markovian environment.
In this paper, dynamics of a qubit in an external laser field is investigated for the non-Markov environment described by an Ornstein-Uhlenbeck process. A non-linear non-Markovian stochastic Schrödinger equation is derived for the quantum system. The stochastic equation is preserved for a positive semi-definite of the density matrix and its trace. By the numerical solution of the equation, the probability of finding the system in the excited state and the influence of non-Markov noise parameters on this probability are studie.