Measurement of many-body chaos using a quantum clock
By Guanyu Zhu, M. Hafezi, T. Grover. 2016
145 citations recorded by the source corpus.
There has been recent progress in understanding chaotic features in many-body quantum systems. Motivated by the scrambling of information in black holes, it has been suggested that the time dependence of out-of-time-ordered (OTO) correlation functions such as $\langle O_2(t) O_1(0) O_2(t) O_1(0) \rangle $ is a faithful measure of quantum chaos. Experimentally, these correlators are challenging to access since they apparently require access to both forward and backward time evolution with the system Hamiltonian. Here, we propose a protocol to measure such OTO correlators using an ancilla which controls the direction of time. Specifically, by coupling the state of ancilla to the system Hamiltonian of interest, we can emulate the forward and backward time propagation, where the ancilla plays the role of a 'quantum clock'. Within this scheme, the continuous evolution of the entire system (the system of interest and the ancilla) is governed by a time-independent Hamiltonian. Our protocol is immune to errors that could occur when the direction of time evolution is externally controlled by a classical switch.
Subfields: Artificial Intelligence, Atomic and Molecular Physics, and Optics, Statistical and Nonlinear Physics
View Paper: https://www.semanticscholar.org/paper/9905bb3d91d3ab8422a3a220200b57727ddfeba9
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In Artificial Intelligence
In Atomic and Molecular Physics, and Optics
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Citations in the corpus
- Operator Spreading in Random Unitary Circuits (2017, background): “[52] Guanyu Zhu, Mohammad Hafezi, and Tarun Grover, “Measurement of many-body chaos using a quantum clock,” Physical Review A 94, 062329 (2016).”
- Random Quantum Circuits (2022, background): “OTOCs have been addressed in a range of experiments (181, 182, 183, 184, 105).”
- Measuring out-of-time-order correlators on a nuclear magnetic resonance quantum simulator (2016, background): “[21] Guanyu Zhu, Mohammad Hafezi, and Tarun Grover, “Measurement of many-body chaos using a quantum clock,” Phys.”
- Onset of many-body chaos in the $O(N)$ model (2017, background): “treme, disordered quantum systems typically scramble much more slowly than their clean counterparts [22] [23] [24] [25] [26] [27]. Several experimental proposals have also appeared recently [28] [29] [30] that enable one to measure OTO correlators and scrambling and three preliminary experiments hav”
- Many-body localization: An introduction and selected topics (2017, unknown): “What about experiments? Several protocols have been proposed to measure the OTOC, where the needed reversal of time is often performed using an ancilla/switch/control degree of freedom [227, 228, 229].”