scholarly journals Time-Reversal Symmetry and Arrow of Time in Quantum Mechanics of Open Systems

Entropy ◽  
2019 ◽  
Vol 21 (4) ◽  
pp. 380 ◽  
Author(s):  
Naomichi Hatano ◽  
Gonzalo Ordonez
Keyword(s):  
Time Reversal ◽  
Quantum Dynamics ◽  
Open Systems ◽  
Open Quantum Systems ◽  
Functional Space ◽  
Time Reversal Symmetry ◽  
Arrow Of Time ◽  
Initial State ◽  
Resonant States ◽  
Complex Eigenvalues

It is one of the most important and long-standing issues of physics to derive the irreversibility out of a time-reversal symmetric equation of motion. The present paper considers the breaking of the time-reversal symmetry in open quantum systems and the emergence of an arrow of time. We claim that the time-reversal symmetric Schrödinger equation can have eigenstates that break the time-reversal symmetry if the system is open in the sense that it has at least a countably infinite number of states. Such eigenstates, namely the resonant and anti-resonant states, have complex eigenvalues. We show that, although these states are often called “unphysical”, they observe the probability conservation in a particular way. We also comment that the seemingly Hermitian Hamiltonian is non-Hermitian in the functional space of the resonant and anti-resonant states, and hence there is no contradiction in the fact that it has complex eigenvalues. We finally show how the existence of the states that break the time-reversal symmetry affects the quantum dynamics. The dynamics that starts from a time-reversal symmetric initial state is dominated by the resonant states for t > 0 ; this explains the phenomenon of the arrow of time, in which the decay excels the growth. The time-reversal symmetry holds in that the dynamic ending at a time-reversal symmetric final state is dominated by the anti-resonant states for t < 0 .

scholarly journals Generation of Quantum Correlations in Bipartite Gaussian Open Quantum Systems

2018 ◽  
Vol 173 ◽  
pp. 01006 ◽  
Author(s):  
Aurelian Isar
Keyword(s):  
Open Systems ◽  
Thermal Environment ◽  
Open Quantum Systems ◽  
Quantum Correlations ◽  
Quantum Systems ◽  
Thermal Bath ◽  
Initial State ◽  
Entanglement Generation ◽  
Strength Of Interaction ◽  
Zero Values

We describe the generation of quantum correlations (entanglement, discord and steering) in a system composed of two coupled non-resonant bosonic modes immersed in a common thermal reservoir, in the framework of the theory of open systems. We show that for separable initial squeezed thermal states entanglement generation may take place, for definite values of squeezing parameter, average photon numbers, temperature of the thermal bath, dissipation constant and strength of interaction between the two bosonic modes. We also show that for initial uni-modal squeezed states Gaussian discord can be generated for all non-zero values of the strength of interaction between the modes. Likewise, for an initial separable state, a generation of Gaussian steering may take place temporarily, for definite values of the parameters characterizing the initial state and the thermal environment, and the strength of coupling between the two modes.

scholarly journals Active gelation breaks time-reversal-symmetry of mitotic chromosome mechanics

2018 ◽  
Author(s):  
Matthäus Mittasch ◽  
Anatol W. Fritsch ◽  
Michael Nestler ◽  
Juan M. Iglesias-Artola ◽  
Kaushikaram Subramanian ◽  
...  
Keyword(s):  
Symmetry Breaking ◽  
Time Reversal ◽  
Mitotic Chromosome ◽  
Metaphase Plate ◽  
Time Reversal Symmetry ◽  
Newtonian Mechanics ◽  
Arrow Of Time ◽  
Cell Nuclei ◽  
Mitotic Chromosomes ◽  
Daughter Cells

AbstractIn cell division, mitosis is the phase in which duplicated sets of chromosomes are mechanically aligned to form the metaphase plate before being segregated in two daughter cells. Irreversibility is a hallmark of this process, despite the fundamental laws of Newtonian mechanics being time symmetric.Here we show experimentally that mitotic chromosomes receive the arrow of time by time-reversal-symmetry breaking of the underlying mechanics in prometaphase. By optically inducing hydrodynamic flows within prophase nuclei, we find that duplicated chromatid pairs initially form a fluid suspension in the nucleoplasm: although showing little motion on their own, condensed chromosomes are free to move through the nucleus in a time-reversible manner. Actively probing chromosome mobility further in time, we find that this viscous suspension of chromatin transitions into a gel after nuclear breakdown. This gel state, in which chromosomes cannot be moved by flows, persists even when chromosomes start moving to form the metaphase plate. Complemented by minimal reconstitution experiments, our active intra-nuclear micro-rheology reveals time-reversal-symmetry breaking of chromosome mechanics to be caused by the transition from a purely fluid suspension into an active gel.Graphical abstractOne sentence summaryFlows induced in living cell nuclei reveal the rheological changes that bring chromosomes under mechanical control during mitosis.

scholarly journals Fermionic duality: General symmetry of open systems with strong dissipation and memory

2021 ◽  
Vol 11 (3) ◽  
Author(s):  
Valentin Bruch ◽  
Konstantin Nestmann ◽  
Jens Schulenborg ◽  
Maarten Wegewijs
Keyword(s):  
Time Evolution ◽  
Quantum Dynamics ◽  
Open Systems ◽  
Broad Class ◽  
Open Quantum Systems ◽  
Causal Structure ◽  
Wide Band ◽  
Quantum Systems ◽  
Strong Interactions ◽  
General Symmetry

We consider the exact time-evolution of a broad class of fermionic open quantum systems with both strong interactions and strong coupling to wide-band reservoirs. We present a nontrivial fermionic duality relation between the evolution of states (Schrödinger) and of observables (Heisenberg). We show how this highly nonintuitive relation can be understood and exploited in analytical calculations within all canonical approaches to quantum dynamics, covering Kraus measurement operators, the Choi-Jamiołkowski state, time-convolution and convolutionless quantum master equations and generalized Lindblad jump operators. We discuss the insights this offers into the divisibility and causal structure of the dynamics and the application to nonperturbative Markov approximations and their initial-slip corrections. Our results underscore that predictions for fermionic models are already fixed by fundamental principles to a much greater extent than previously thought.

scholarly journals Description of Quantum Dynamics of Open Systems Based on Collision-Like Models

2005 ◽  
Vol 12 (01) ◽  
pp. 81-91 ◽  
Author(s):  
Mário Ziman ◽  
Peter Štelmachovič ◽  
Vladimír Bužek
Keyword(s):  
Quantum System ◽  
Quantum Dynamics ◽  
Open Systems ◽  
Open Quantum Systems ◽  
Quantum Systems ◽  
Master Equations ◽  
Discrete Dynamics ◽  
Completely Positive ◽  
Semigroup Property ◽  
System A

Master equations in the Lindblad form describe evolution of open quantum systems that are completely positive and simultaneously have a semigroup property. We analyze the possibility to derive this type of master equations from an intrinsically discrete dynamics that is modelled as a sequence of collisions between a given quantum system (a qubit) with particles that form the environment. In order to illustrate our approach we analyze in detail how the process of an exponential decay and the process of decoherence can be derived from a collision-like model in which particular collisions are described by SWAP and controlled-NOT interactions, respectively.

scholarly journals “What Is Life?”: Open Quantum Systems Approach

2021 ◽  
Author(s):  
Andrei Khrennikov ◽  
Irina Basieva
Keyword(s):  
Steady State ◽  
Quantum Dynamics ◽  
Systems Approach ◽  
Open Quantum Systems ◽  
Quantitative Measure ◽  
Second Law Of Thermodynamics ◽  
Quantum Systems ◽  
Order Structure ◽  
Initial State ◽  
Open Quantum

Abstract Recently the quantum formalism and methodology started to be applied to modeling of information processing in biosystems, mainly to the process of decision making and psychological behavior (but some applications to microbiology and genetics are considered as well). Since a living system is fundamentally open (an isolated biosystem is dead), the theory of open quantum systems is the most powerful tool for life-modeling. In this paper, we turn to the famous Schrödinger book “What is life?” and reformulate his speculations in terms of this theory. Schrödinger pointed toorder preservation as one of the main distinguishing features of biosystems. Entropy is the basic quantitative measure of order. In physical systems, entropy has the tendency to increase (Second Law of Thermodynamics for isolated classical systems and dissipation in open classical and quantum systems). Schrödinger emphasized the ability of biosystems to beat this tendency. We demonstrate that systems processing information in the quantum-like way can preservethe order-structure expressed by the quantum (von Neumann or linear) entropy. We emphasize the role of the special class of quantum dynamics and initial states generating the camel-like graphs for entropy-evolution in the process of interaction with a new environment ℰ: 1) entropy (disorder) increasing in the process of adaptation to the specific features of ℰ; 2) entropy decreasing (order increasing) resulting from adaptation; 3) the restoration of order or even its increase for limiting steady state. In the latter case the steady state entropy can be even lower than the entropy of the initial state.

scholarly journals Rephasing Invariant for Three-Neutrino Oscillations Governed by a Non-Hermitian Hamiltonian

Symmetry ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1285
Author(s):  
Dmitry V. Naumov ◽  
Vadim A. Naumov ◽  
Dmitry S. Shkirmanov
Keyword(s):  
Time Reversal ◽  
Quantum Dynamics ◽  
Neutrino Oscillations ◽  
Time Reversal Symmetry ◽  
Direct Connection ◽  
Neutrino Mixing ◽  
Mixing Angles ◽  
Dirac Neutrino ◽  
Absorbing Media ◽  
Neutrino Propagation

Time-reversal symmetry is broken for mixed and possibly unstable Dirac neutrino propagation through absorbing media. This implies that interplay between the neutrino mixing, refraction, absorption and/or decay can be described by non-Hermitian quantum dynamics. We derive an identity which sets up direct connection between the fundamental neutrino parameters (mixing angles, CP-violating phase, mass-squared splittings) in vacuum and their effective counterparts in matter.

scholarly journals ASYMPTOTIC ENTANGLEMENT IN OPEN QUANTUM SYSTEMS

2008 ◽  
Vol 06 (supp01) ◽  
pp. 689-694 ◽  
Author(s):  
AURELIAN ISAR
Keyword(s):  
Open Systems ◽  
Open Quantum Systems ◽  
Continuous Variable ◽  
Harmonic Oscillators ◽  
Asymptotic State ◽  
Input State ◽  
Initial State ◽  
Bipartite State ◽  
Time Regime ◽  
Long Time

In the framework of the theory of open systems based on completely positive quantum dynamical semigroups, we solve in the asymptotic long-time regime the master equation for two independent harmonic oscillators interacting with an environment. We give a description of the continuous-variable asymptotic entanglement in terms of the covariance matrix of the considered subsystem for an arbitrary Gaussian input state. Using Peres–Simon necessary and sufficient condition for separability of two-mode Gaussian states, we show that for certain classes of environments the initial state evolves asymptotically to an entangled equilibrium bipartite state, while for other values of the coefficients describing the environment, the asymptotic state is separable. We calculate also the logarithmic negativity characterizing the degree of entanglement of the asymptotic state.

scholarly journals Quantum thermo-dynamical construction for driven open quantum systems

Quantum ◽  
2021 ◽  
Vol 5 ◽  
pp. 590
Author(s):  
Roie Dann ◽  
Ronnie Kosloff
Keyword(s):  
Quantum Dynamics ◽  
Open Systems ◽  
Open Quantum Systems ◽  
Axiomatic Approach ◽  
Classical Description ◽  
Global Coherence ◽  
Physical Limit ◽  
Transient Control ◽  
Initial Control

Quantum dynamics of driven open systems should be compatible with both quantum mechanic and thermodynamic principles. By formulating the thermodynamic principles in terms of a set of postulates we obtain a thermodynamically consistent master equation. Following an axiomatic approach, we base the analysis on an autonomous description, incorporating the drive as a large transient control quantum system. In the appropriate physical limit, we derive the semi-classical description, where the control is incorporated as a time-dependent term in the system Hamiltonian. The transition to the semi-classical description reflects the conservation of global coherence and highlights the crucial role of coherence in the initial control state. We demonstrate the theory by analyzing a qubit controlled by a single bosonic mode in a coherent state.

Sign in / Sign up

Export Citation Format

Share Document