English
Related papers

Related papers: Quantum complexity phase transitions in monitored …

200 papers

Monitored quantum circuits can exhibit an entanglement transition as a function of the rate of measurements, stemming from the competition between scrambling unitary dynamics and disentangling projective measurements. We study how…

Disordered Systems and Neural Networks · Physics 2022-10-11 Utkarsh Agrawal , Aidan Zabalo , Kun Chen , Justin H. Wilson , Andrew C. Potter , J. H. Pixley , Sarang Gopalakrishnan , Romain Vasseur

We introduce a quantum version for the statistical complexity measure, in the context of quantum information theory, and use it as a signalling function of quantum order-disorder transitions. We discuss the possibility for such transitions…

Monitored quantum systems evolve along stochastic trajectories correlated with the observer's knowledge of the system's state. Under such dynamics, certain quantum resources like entanglement may depend on the observer's state of knowledge.…

Quantum Physics · Physics 2024-09-04 Christian Carisch , Oded Zilberberg , Alessandro Romito

The evolution of a quantum system subject to measurements can be described by stochastic quantum trajectories of pure states. Instead, the ensemble average over trajectories is a mixed state evolving via a master equation. Both descriptions…

Quantum Physics · Physics 2024-02-22 Christian Carisch , Alessandro Romito , Oded Zilberberg

We study localization properties of continuously monitored dynamics and associated measurement-induced phase transitions in disordered quantum many-body systems on the basis of the quantum trajectory approach. By calculating the fidelity…

Statistical Mechanics · Physics 2023-06-09 Kazuki Yamamoto , Ryusuke Hamazaki

We present methods for evaluating the rate of change in quantities during quantum evolution due to coupling to the environment (dissipation hereafter). The protocol is based on repeating a given quantum circuit (or quantum operation) twice,…

Quantum Physics · Physics 2021-12-02 Raam Uzdin

Quantum computing can provide speedups in solving many problems as the evolution of a quantum system is described by a unitary operator in an exponentially large Hilbert space. Such unitary operators change the phase of their eigenstates…

Quantum Physics · Physics 2024-01-23 Youle Wang , Lei Zhang , Zhan Yu , Xin Wang

Entanglement is one of the physical properties of quantum systems responsible for the computational hardness of simulating quantum systems. But while the runtime of specific algorithms, notably tensor network algorithms, explicitly depends…

Monitored quantum circuits in which entangling unitary dynamics compete with projective local measurements can host measurement-induced phase transitions witnessed by entanglement measures at late times. Adding feedback conditioned on the…

Quantum Physics · Physics 2025-04-17 Haining Pan , Thomas Iadecola , E. M. Stoudenmire , J. H. Pixley

Nascent quantum computers motivate the exploration of quantum many-body systems in nontraditional scenarios. For example, it has become natural to explore the dynamics of systems evolving under both unitary evolution and measurement. Such…

Statistical Mechanics · Physics 2024-03-15 Nicholas O'Dea , Alan Morningstar , Sarang Gopalakrishnan , Vedika Khemani

We explore, both analytically and numerically, the quantum dynamics of a many-body free-fermion system subjected to local density measurements. We begin by extending the mapping to the nonlinear sigma-model (NLSM) field theory for the case…

Disordered Systems and Neural Networks · Physics 2026-04-22 Igor Poboiko , Alexander D. Mirlin

Entanglement is the key feature of many-body quantum systems, and the development of new tools to probe it in the laboratory is an outstanding challenge. Measuring the entropy of different partitions of a quantum system provides a way to…

We study the entanglement dynamics in a generic quantum automaton circuit subjected to projective measurements. We design an efficient algorithm which not only allows us to perform large scale simulation for the R\'enyi entropy but also…

Quantum Physics · Physics 2021-01-07 Jason Iaconis , Andrew Lucas , Xiao Chen

We propose a measure of quantum state complexity defined by minimizing the spread of the wave-function over all choices of basis. Our measure is controlled by the "survival amplitude" for a state to remain unchanged, and can be efficiently…

High Energy Physics - Theory · Physics 2022-09-14 Vijay Balasubramanian , Pawel Caputa , Javier Magan , Qingyue Wu

Quantum metrology based on quantum entanglement and quantum coherence improves the accuracy of measurement. In this paper, we briefly review the schemes of quantum metrology in various complex systems, including non-Markovian noise,…

Quantum Physics · Physics 2024-01-18 Qing Ai , Yang-Yang Wang , Jing Qiu

Reliable processing of quantum information for developing quantum technologies requires precise control of out-of-equilibrium many-bodysystems. This is a highly challenging task as the fragility of quantum states to external perturbations…

The intensely studied measurement-induced entanglement phase transition has become a hallmark of non-unitary quantum many-body dynamics. Usually, such a transition only shows up at the level of each individual quantum trajectory, and is…

Statistical Mechanics · Physics 2023-07-26 Vikram Ravindranath , Yiqiu Han , Zhi-Cheng Yang , Xiao Chen

Weak measurements performed between quantum state preparation and post-selection result in complex values for self-adjoint operators, corresponding to complex conditional probabilities for the projections on specific eigenstates. In this…

Quantum Physics · Physics 2011-10-14 Holger F. Hofmann

Entanglement transitions in quantum dynamics present a novel class of phase transitions in non-equilibrium systems. When a many-body quantum system undergoes unitary evolution interspersed with monitored random measurements, the…

Quantum Physics · Physics 2021-10-08 Oliver Lunt , Marcin Szyniszewski , Arijeet Pal

Quantifying quantum states' complexity is a key problem in various subfields of science, from quantum computing to black-hole physics. We prove a prominent conjecture by Brown and Susskind about how random quantum circuits' complexity…