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The study of many-body quantum dynamics in strongly-correlated systems is extremely challenging. To date few numerical methods exist which are capable of simulating the non-equilibrium dynamics of two-dimensional quantum systems, in part…

Quantum Physics · Physics 2024-09-17 S. J. Thomson , J. Eisert

Accurate control of quantum systems requires precise measurement of the parameters that govern the dynamics, including control fields and interactions with the environment. Parameters will drift in time and experiments interleave protocols…

Quantum Physics · Physics 2020-02-11 Swarnadeep Majumder , Leonardo Andreta de Castro , Kenneth R. Brown

We provide a protocol to measure out-of-time-order correlation functions. These correlation functions are of theoretical interest for diagnosing the scrambling of quantum information in black holes and strongly interacting quantum systems…

Quantum Physics · Physics 2016-11-02 Brian Swingle , Gregory Bentsen , Monika Schleier-Smith , Patrick Hayden

Measurement-induced phase transitions arise due to a competition between the scrambling of quantum information in a many-body system and local measurements. In this work we investigate these transitions in different classes of fast…

Quantum Physics · Physics 2022-03-29 Tomohiro Hashizume , Gregory Bentsen , Andrew J. Daley

We study quantum information scrambling in spin models with both long-range all-to-all and short-range interactions. We argue that a simple global, spatially homogeneous interaction together with local chaotic dynamics is sufficient to give…

One of the main challenges in building a quantum processor is to characterize the environmental noise. Noise characterization can be achieved by exploiting different techniques, such as randomization where several sequences of random…

Quantum Physics · Physics 2020-11-04 Elena Ferraro , Marco De Michielis

Quantum phase estimation is a central primitive in quantum algorithms and sensing, where performance is governed by the sensitivity of measurement signals to the target parameter. While existing methods have developed increasingly…

Quantum Physics · Physics 2026-04-02 Zikang Jia , Suying Liu , Yulong Dong

The quantum neural network is one of the promising applications for near-term noisy intermediate-scale quantum computers. A quantum neural network distills the information from the input wavefunction into the output qubits. In this Letter,…

Disordered Systems and Neural Networks · Physics 2020-05-27 Huitao Shen , Pengfei Zhang , Yi-Zhuang You , Hui Zhai

A central challenge in analog quantum simulation is to characterize desirable physical properties of quantum states produced in experiments. However, in conventional approaches, the extraction of arbitrary information requires performing…

Quantum Physics · Physics 2023-04-04 Minh C. Tran , Daniel K. Mark , Wen Wei Ho , Soonwon Choi

The development and spread of entanglement in complex quantum systems is central to exploring many-body phenomena out of equilibrium. Measuring entanglement dynamics can shed light on information scrambling and thermalisation, namely on…

In this work, we consider the problem of online (real-time, single-shot) estimation of static or slow-varying parameters along quantum trajectories in quantum dynamical systems. Based on the measurement signal of a continuously-monitored…

Quantum Physics · Physics 2024-06-19 Henrik Glavind Clausen , Pierre Rouchon , Rafal Wisniewski

The simulation of complex quantum systems on a quantum computer is studied, taking the kicked Harper model as an example. This well-studied system has a rich variety of dynamical behavior depending on parameters, displays interesting…

Quantum Physics · Physics 2007-05-23 Benjamin Levi , Bertrand Georgeot

We study the problem of learning the parameters for the Hamiltonian of a quantum many-body system, given limited access to the system. In this work, we build upon recent approaches to Hamiltonian learning via derivative estimation. We…

Quantum Physics · Physics 2024-01-10 Andi Gu , Lukasz Cincio , Patrick J. Coles

Projective measurement, a basic operation in quantum mechanics, can induce seemingly nonlocal effects. In this work, we analyze such effects in many-body systems by studying the non-equilibrium dynamics of weakly monitored quantum circuits,…

Statistical Mechanics · Physics 2024-06-19 Shengqi Sang , Zhi Li , Timothy H. Hsieh , Beni Yoshida

We propose and analyze a sample-efficient protocol to estimate the fidelity between an experimentally prepared state and an ideal target state, applicable to a wide class of analog quantum simulators without advanced sophisticated…

Quantum Physics · Physics 2023-09-14 Daniel K. Mark , Joonhee Choi , Adam L. Shaw , Manuel Endres , Soonwon Choi

We introduce a model of non-unitary quantum dynamics that exhibits infinitely long-lived discrete spatiotemporal order robust against any unitary or dissipative perturbation. Ergodicity is evaded by combining a sequence of projective…

Quantum Physics · Physics 2022-08-31 Max McGinley , Sthitadhi Roy , S. A. Parameswaran

We provide and experimentally demonstrate an accreditation protocol that upper-bounds the variation distance between noisy and noiseless probability distributions of the outputs of arbitrary quantum computations. We accredit the outputs of…

Quantum Physics · Physics 2021-10-13 Samuele Ferracin , Seth T. Merkel , David McKay , Animesh Datta

Characterising quantum processes is a key task in and constitutes a challenge for the development of quantum technologies, especially at the noisy intermediate scale of today's devices. One method for characterising processes is randomised…

Quantum Physics · Physics 2018-10-31 Ingo Roth , Richard Kueng , Shelby Kimmel , Yi-Kai Liu , David Gross , Jens Eisert , Martin Kliesch

Randomized benchmarking is routinely used as an efficient method for characterizing the performance of sets of elementary logic gates in small quantum devices. In the measurement-based model of quantum computation, logic gates are…

Quantum Physics · Physics 2016-09-05 Rafael N. Alexander , Peter S. Turner , Stephen D. Bartlett

Understanding various phenomena in non-equilibrium dynamics of closed quantum many-body systems, such as quantum thermalization, information scrambling, and nonergodic dynamics, is a crucial for modern physics. Using a ladder-type…