scholarly journals Noise representations of open system dynamics

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Piotr Szańkowski ◽  
Łukasz Cywiński
Keyword(s):  
System Dynamics ◽  
Quantum System ◽  
Open System ◽  
Degrees Of Freedom ◽  
Sufficient Criterion ◽  
Specific System ◽  
Field Representation ◽  
System Environment ◽  
Back Action ◽  
The Given

AbstractWe analyze the conditions under which the dynamics of a quantum system open to a given environment can be simulated with an external noisy field that is a surrogate for the environmental degrees of freedom. We show that such a field is either a subjective or an objective surrogate; the former is capable of simulating the dynamics only for the specific system–environment arrangement, while the latter is an universal simulator for any system interacting with the given environment. Consequently, whether the objective surrogate field exists and what are its properties is determined exclusively by the environment. Thus, we are able to formulate the sufficient criterion for the environment to facilitate its surrogate, and we identify a number of environment types that satisfy it. Finally, we discuss in what sense the objective surrogate field representation can be considered classical and we explain its relation to the formation of system–environment entanglement, and the back-action exerted by the system onto environment.

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

Quantum ◽  
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.

scholarly journals Purity as a witness for initial system-environment correlations in open-system dynamics

2011 ◽  
Vol 84 (4) ◽  
Author(s):  
D Z. Rossatto ◽  
T. Werlang ◽  
L K. Castelano ◽  
C J. Villas-Boas ◽  
F F. Fanchini
Keyword(s):  
System Dynamics ◽  
Open System ◽  
Initial System ◽  
System Environment

scholarly journals Witness for initial system-environment correlations in open-system dynamics

2010 ◽  
Vol 92 (6) ◽  
pp. 60010 ◽  
Author(s):  
E.-M. Laine ◽  
J. Piilo ◽  
H.-P. Breuer
Keyword(s):  
System Dynamics ◽  
Open System ◽  
Initial System ◽  
System Environment

scholarly journals Testing automatic methods to predict free binding energy of host–guest complexes in SAMPL7 challenge

2021 ◽  
Vol 35 (2) ◽  
pp. 209-222
Author(s):  
Dylan Serillon ◽  
Carles Bo ◽  
Xavier Barril
Keyword(s):  
Degrees Of Freedom ◽  
Binding Free Energy ◽  
Binding Mode ◽  
Specific System ◽  
New Host ◽  
Guest Molecules ◽  
Host Guest Complex ◽  
Automatic Methods ◽  
Material Sciences ◽  
Fundamental Direction

AbstractThe design of new host–guest complexes represents a fundamental challenge in supramolecular chemistry. At the same time, it opens new opportunities in material sciences or biotechnological applications. A computational tool capable of automatically predicting the binding free energy of any host–guest complex would be a great aid in the design of new host systems, or to identify new guest molecules for a given host. We aim to build such a platform and have used the SAMPL7 challenge to test several methods and design a specific computational pipeline. Predictions will be based on machine learning (when previous knowledge is available) or a physics-based method (otherwise). The formerly delivered predictions with an RMSE of 1.67 kcal/mol but will require further work to identify when a specific system is outside of the scope of the model. The latter is combines the semiempirical GFN2B functional, with docking, molecular mechanics, and molecular dynamics. Correct predictions (RMSE of 1.45 kcal/mol) are contingent on the identification of the correct binding mode, which can be very challenging for host–guest systems with a large number of degrees of freedom. Participation in the blind SAMPL7 challenge provided fundamental direction to the project. More advanced versions of the pipeline will be tested against future SAMPL challenges.

scholarly journals Quantum system dynamics with a weakly nonlinear Josephson junction bath

2021 ◽  
Vol 103 (8) ◽  
Author(s):  
Jing Yang ◽  
Étienne Jussiau ◽  
Cyril Elouard ◽  
Karyn Le Hur ◽  
Andrew N. Jordan
Keyword(s):  
System Dynamics ◽  
Josephson Junction ◽  
Quantum System ◽  
Weakly Nonlinear

THE QUANTUM TRAJECTORY APPROACH TO GEOMETRIC PHASE FOR OPEN SYSTEMS

2005 ◽  
Vol 20 (22) ◽  
pp. 1635-1654 ◽  
Author(s):  
ANGELO CAROLLO
Keyword(s):  
Quantum System ◽  
Open System ◽  
Geometric Phase ◽  
Open Systems ◽  
Quantum Trajectory ◽  
Operational Method ◽  
Markovian Approximation ◽  
Physical Systems ◽  
Quantum Jump ◽  
Trajectory Approach

The quantum jump method for the calculation of geometric phase is reviewed. This is an operational method to associate a geometric phase to the evolution of a quantum system subjected to decoherence in an open system. The method is general and can be applied to many different physical systems, within the Markovian approximation. As examples, two main source of decoherence are considered: dephasing and spontaneous decay. It is shown that the geometric phase is to very large extent insensitive to the former, i.e. it is independent of the number of jumps determined by the dephasing operator.

The Natural Frequencies of Free and Constrained Non-Uniform Beams

1960 ◽  
Vol 64 (599) ◽  
pp. 697-699 ◽  
Author(s):  
R. P. N. Jones ◽  
S. Mahalingam
Keyword(s):  
Degrees Of Freedom ◽  
Natural Frequencies ◽  
Ritz Method ◽  
Normal Modes ◽  
Iteration Process ◽  
Conservative System ◽  
Basic System ◽  
Orthogonal Functions ◽  
Added Masses ◽  
The Given

The Rayleigh-Ritz method is well known as an approximate method of determining the natural frequencies of a conservative system, using a constrained deflection form. On the other hand, if a general deflection form (i.e. an unconstrained form) is used, the method provides a theoretically exact solution. An unconstrained form may be obtained by expressing the deflection as an expansion in terms of a suitable set of orthogonal functions, and in selecting such a set, it is convenient to use the known normal modes of a suitably chosen “ basic system.” The given system, whose vibration properties are to be determined, can then be regarded as a “ modified system,” which is derived from the basic system by a variation of mass and elasticity. A similar procedure has been applied to systems with a finite number of degrees of freedom. In the present note the method is applied to simple non-uniform beams, and to beams with added masses and constraints. A concise general solution is obtained, and an iteration process of obtaining a numerical solution is described.

scholarly journals Symmetry in the open-system dynamics of quantum correlations

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Henri Lyyra ◽  
Göktuğ Karpat ◽  
Chuan-Feng Li ◽  
Guang-Can Guo ◽  
Jyrki Piilo ◽  
...  
Keyword(s):  
System Dynamics ◽  
Open System ◽  
Quantum Correlations
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