Related papers: Effective dynamics from minimising dissipation

Effective dynamics from minimising dissipation

URL: http://arxiv.org/abs/2412.10216v1
Date: Fri, 13 Dec 2024 15:39:21 GMT
Title: Effective dynamics from minimising dissipation
Authors: Antonio F. Rotundo, Paolo Perinotti, Alessandro Bisio,
Abstract summary: It is known that the same physical system can be described by different effective theories depending on the scale at which it is observed. In this work, we formulate a prescription for finding the unitary that best approximates the large scale dynamics of a quantum system evolving discretely in time.
Score: 45.279573215172285
License:
Abstract: It is known that the same physical system can be described by different effective theories depending on the scale at which it is observed. In this work, we formulate a prescription for finding the unitary that best approximates the large scale dynamics of a quantum system evolving discretely in time, as it is the case for digital quantum simulators. We consider the situation in which the degrees of freedom of the system can be divided between an IR part that we can observe, and a UV part that we cannot observe. Following a principle of minimal dissipation, our goal is to find the unitary dynamics that best approximates the (generally non unitary) time evolution of the IR degrees of freedom. We first prove that when the IR and UV degrees of freedom are weakly coupled, the unitary that maximises the fidelity is given by a mean-field dynamics and the error is given by a sum of energy variances. We then apply our results to a one dimensional quantum walk, which is known to reproduce the Dirac equation in the small mass and momenta limit. We find that in this limit the effective IR dynamics is obtained by a mass redefinition.

Related papers

Matrix product state approximations to quantum states of low energy variance [0.3277163122167433]
We show how to efficiently simulate pure quantum states in one dimensional systems with finite energy density and vanishingly small energy fluctuations. We prove that there exist states with a very narrow support in the bulk of the spectrum that still have moderate entanglement entropy.
arXiv Detail & Related papers (2023-07-11T12:10:15Z)
Quantum Lyapunov exponent in dissipative systems [68.8204255655161]
The out-of-time order correlator (OTOC) has been widely studied in closed quantum systems. We study the interplay between these two processes. The OTOC decay rate is closely related to the classical Lyapunov.
arXiv Detail & Related papers (2022-11-11T17:06:45Z)
Gauge-Invariant Semi-Discrete Wigner Theory [0.0]
A gauge-invariant Wigner quantum mechanical theory is obtained by applying the Weyl-Stratonovich transform to the von Neumann equation for the density matrix. We derive the evolution equation for the linear electromagnetic case and show that it significantly simplifies for a limit dictated by the long coherence length behavior.
arXiv Detail & Related papers (2022-08-19T08:19:09Z)
Extended Uncertainty Principle via Dirac Quantization [0.0]
We show that generic infrared (IR) modifications arise when we describe quantum theory in curved spacetime. We study particle dynamics in an arbitrary curved spacetime by embedding them in a higher-dimensional flat geometry.
arXiv Detail & Related papers (2022-04-04T18:23:30Z)
Dispersive readout of molecular spin qudits [68.8204255655161]
We study the physics of a magnetic molecule described by a "giant" spin with multiple $d > 2$ spin states. We derive an expression for the output modes in the dispersive regime of operation. We find that the measurement of the cavity transmission allows to uniquely determine the spin state of the qudits.
arXiv Detail & Related papers (2021-09-29T18:00:09Z)
Anomalous statistics of laser-cooled atoms in dissipative optical lattices [0.0]
A century ago it was realized that an extension to this type of dynamics can be obtained in the form of anomalous" diffusion. Laser-cooled atomic ensembles can be used as a test bed for such dynamics.
arXiv Detail & Related papers (2021-07-20T14:19:58Z)
Visualizing spinon Fermi surfaces with time-dependent spectroscopy [62.997667081978825]
We propose applying time-dependent photo-emission spectroscopy, an established tool in solid state systems, in cold atom quantum simulators. We show in exact diagonalization simulations of the one-dimensional $t-J$ model that the spinons start to populate previously unoccupied states in an effective band structure. The dependence of the spectral function on the time after the pump pulse reveals collective interactions among spinons.
arXiv Detail & Related papers (2021-05-27T18:00:02Z)
Evolution of a Non-Hermitian Quantum Single-Molecule Junction at Constant Temperature [62.997667081978825]
We present a theory for describing non-Hermitian quantum systems embedded in constant-temperature environments. We find that the combined action of probability losses and thermal fluctuations assists quantum transport through the molecular junction.
arXiv Detail & Related papers (2021-01-21T14:33:34Z)
The role of boundary conditions in quantum computations of scattering observables [58.720142291102135]
Quantum computing may offer the opportunity to simulate strongly-interacting field theories, such as quantum chromodynamics, with physical time evolution. As with present-day calculations, quantum computation strategies still require the restriction to a finite system size. We quantify the volume effects for various $1+1$D Minkowski-signature quantities and show that these can be a significant source of systematic uncertainty.
arXiv Detail & Related papers (2020-07-01T17:43:11Z)
Universal Error Bound for Constrained Quantum Dynamics [0.0]
We establish an observable-based error bound for a constrained-dynamics approximation in generic gapped quantum systems. Our work establishes a universal and rigorous result concerning nonequilibrium quantum dynamics.
arXiv Detail & Related papers (2020-01-03T06:25:03Z)

This list is automatically generated from the titles and abstracts of the papers in this site.