Exact, Average, and Broken Symmetries in a Simple Adaptive Monitored Circuit

• URL: http://arxiv.org/abs/2312.17309v1
• Date: Thu, 28 Dec 2023 18:56:23 GMT
• Title: Exact, Average, and Broken Symmetries in a Simple Adaptive Monitored Circuit
• Authors: Zhi Li, Zhu-Xi Luo
• Abstract summary: Quantum circuits with measurements have emerged as a platform for novel states of matter intrinsically out of equilibrium. Can symmetry be used as an organizing principle for these novel states, their phases and phase transitions? We give an affirmative answer in a simple adaptive monitored circuit, which hosts an ordering transition in addition to a separate entanglement transition.
• Score: 3.7536679189225373
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: Symmetry is a powerful tool for understanding phases of matter in equilibrium. Quantum circuits with measurements have recently emerged as a platform for novel states of matter intrinsically out of equilibrium. Can symmetry be used as an organizing principle for these novel states, their phases and phase transitions? In this work, we give an affirmative answer to this question in a simple adaptive monitored circuit, which hosts an ordering transition in addition to a separate entanglement transition, upon tuning a single parameter. Starting from a symmetry-breaking initial state, depending on the tuning parameter, the steady state could (i) remain symmetry-broken, (ii) exhibit the average symmetry in the ensemble of trajectories, or (iii) exhibit the exact symmetry for each trajectory. The ordering transition is mapped to the transition in a classical majority vote model, described by the Ising universality class, while the entanglement transition lies in the percolation class. Numerical simulations are further presented to support the analytical understandings.

Related papers

• Strong-to-weak Symmetry Breaking and Entanglement Transitions [6.095133268764501]
  We study the entanglement transition from the perspective of strong-to-weak symmetry breaking. Our results provide a novel viewpoint on the entanglement transition under symmetry constraints.
  arXiv  Detail & Related papers  (2024-11-08T06:42:28Z)
• Spontaneous PT-symmetry breaking transitions under the influence of noise in an optomechanical system [0.0]
  Spontaneous symmetry breaking is a phenomenon of an alteration of a state symmetry without a change in the system symmetry. In this letter, we consider the behavior of an optomechanical system with an exceptional point under the influence of noise.
  arXiv  Detail & Related papers  (2024-08-09T06:05:59Z)
• Non-equilibrium dynamics of charged dual-unitary circuits [44.99833362998488]
  interplay between symmetries and entanglement in out-of-equilibrium quantum systems is currently at the centre of an intense multidisciplinary research effort. We show that one can introduce a class of solvable states, which extends that of generic dual unitary circuits. In contrast to the known class of solvable states, which relax to the infinite temperature state, these states relax to a family of non-trivial generalised Gibbs ensembles.
  arXiv  Detail & Related papers  (2024-07-31T17:57:14Z)
• Geometric Quantum Machine Learning with Horizontal Quantum Gates [41.912613724593875]
  We propose an alternative paradigm for the symmetry-informed construction of variational quantum circuits. We achieve this by introducing horizontal quantum gates, which only transform the state with respect to the directions to those of the symmetry. For a particular subclass of horizontal gates based on symmetric spaces, we can obtain efficient circuit decompositions for our gates through the KAK theorem.
  arXiv  Detail & Related papers  (2024-06-06T18:04:39Z)
• Translation symmetry restoration under random unitary dynamics [0.0]
  We study how certain symmetries of the dynamics that are broken by the initial state are restored at the level of the reduced state of a given subsystem. Here we show that that the same logic can be applied to the restoration of space-time symmetries, and hence can be used to characterise the relaxation of fully generic systems.
  arXiv  Detail & Related papers  (2024-06-06T17:40:22Z)
• Control landscape of measurement-assisted transition probability for a three-level quantum system with dynamical symmetry [77.34726150561087]
  Quantum systems with dynamical symmetries have conserved quantities which are preserved under coherent controls. Incoherent control can increase the maximal attainable transition probability. We show that all critical points are global maxima, global minima, saddle points and second order traps.
  arXiv  Detail & Related papers  (2023-07-14T16:12:21Z)
• Simulating scalar field theories on quantum computers with limited resources [62.997667081978825]
  We present a quantum algorithm for implementing $phi4$ lattice scalar field theory on qubit computers. The algorithm allows efficient $phi4$ state preparation for a large range of input parameters in both the normal and broken symmetry phases.
  arXiv  Detail & Related papers  (2022-10-14T17:28:15Z)
• Quantum Mechanics as a Theory of Incompatible Symmetries [77.34726150561087]
  We show how classical probability theory can be extended to include any system with incompatible variables. We show that any probabilistic system (classical or quantal) that possesses incompatible variables will show not only uncertainty, but also interference in its probability patterns.
  arXiv  Detail & Related papers  (2022-05-31T16:04:59Z)
• Symmetry enriched phases of quantum circuits [0.0]
  Quantum circuits generate a novel ensemble of quantum many-body states. We classify the phases that can be established as steady states. We discuss close analogies to the theory of spin glasses pioneered by Edwards and Anderson.
  arXiv  Detail & Related papers  (2021-02-18T05:44:22Z)
• Breaking strong symmetries in dissipative quantum systems: Bosonic atoms coupled to a cavity [0.0]
  In dissipative quantum systems, strong symmetries can lead to the existence of conservation laws and multiple steady states. We show that for ideal bosons coupled to the cavity multiple steady states exist and in each symmetry sector a dissipative phase transition occurs at a different critical point. We point out the phenomenon of dissipative freezing, the breaking of the conservation law at the level of individual realizations in the presence of the strong symmetry.
  arXiv  Detail & Related papers  (2021-02-04T10:54:31Z)
• Universality of entanglement transitions from stroboscopic to continuous measurements [68.8204255655161]
  We show that the entanglement transition at finite coupling persists if the continuously measured system is randomly nonintegrable. This provides a bridge between a wide range of experimental settings and the wealth of knowledge accumulated for the latter systems.
  arXiv  Detail & Related papers  (2020-05-04T21:45:59Z)

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

This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.