Abstracts

Measuring out-of-time-ordered correlation functions without reversing time evolution

Presenting Author: Philip Blocher, University of New Mexico CQuIC
Contributing Author(s): Serwan Asaad, Vincent Mourik, Mark Johnson, Andrea Morello, Klaus Mølmer.

In recent years out-of-time-ordered correlation functions (OTOCs) have played a crucial role in characterizing the dynamics of quantum information in quantum many-body systems due to their ability to quantify quantum information scrambling. In particular, the relationship between scrambling, entanglement, thermalization, and quantum chaos has been elucidated using OTOCs [2]. However, due to their out-of-time-ordered nature, OTOCs are difficult to measure experimentally and at first glance require the reversal of time evolution in experiments. In this poster we present a novel OTOC measurement protocol that is easy to implement in a range of experimental and theoretical settings. The measurement protocol circumvents the need for the reversal of time evolution by relating the OTOC to the expectation value of a single-time operator in a simple forward time-evolved state [1]. Thus, only a single instance of the system and no auxiliary degrees of freedom are needed. We demonstrate how the protocol accounts for both pure and mixed initial states and extend it to systems that interact with environmental degrees of freedom. Finally, we highlight the application of our protocol with examples from the characterization of scrambling in a driven spin that exhibits quantum chaos. [1] P.D. Blocher, S. Asaad, V. Mourik, M.I. Johnson, A. Morello, and K. Mølmer, arXiv:2003.03980 (2020). [2] R.J. Lewis-Swan, A. Safavi-Naini, J.J. Bollinger, and A.M. Rey, Nat. Commun. 10, 1581 (2019).

Read this article online: https://arxiv.org/abs/2003.03980

(Session 5 : Thursday from 12:00pm-2:00 pm)

 

SQuInT Chief Organizer
Akimasa Miyake, Associate Professor
amiyake@unm.edu

SQuInT Co-Organizer
Brian Smith, Associate Professor
bjsmith@uoregon.edu

SQuInT Local Organizers
Philip Blocher, Postdoc
Pablo Poggi, Research Assistant Professor
Tzula Propp, Postdoc
Jun Takahashi, Postdoc
Cunlu Zhou, Postdoc

SQuInT Founder
Ivan Deutsch, Regents' Professor, CQuIC Director
ideutsch@unm.edu

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