Department of Physics & Astronomy
University of New Mexico

CQuIC Seminars

Quantum Chaos 2020 Series: Decoherence scaling transition in the dynamics of quantum information scrambling

Presented by Gonzalo Álvarez (CAB - CNEA)

A QUANTUM CHAOS SEMINAR presented in a Zoom meeting vetted by CQuIC, organized by Pablo Poggi in collaboration with Pieter Claeys.

Abstract:

Reliable processing of quantum information for developing quantum technologies requires precise control of out-of-equilibrium many-body systems. This is a highly challenging task as the fragility of quantum states to external perturbations increases with the system-size. In this talk, I will report on a series of experimental quantum simulations that allow to quantify the sensitivity of a controlled Hamiltonian evolution to perturbations that drive the system away from the targeted evolution [1,2]. Based on out-of-time order correlations, we demonstrate that the decay-rate of the process fidelity increases with the effective number K of correlated qubits as K^α [2]. As a function of the perturbation strength, we observed a sharp decoherence scaling transition of the exponent α between two distinct dynamical regimes. In the limiting case below the critical perturbation strength, there is not inherent limit to the number of qubits that can be controlled with high fidelity. This may indicate that reliable control of large quantum systems might be possible if the perturbation can be kept below this critical threshold.

[1] Gonzalo A. lvarez, Dieter Suter, and Robin Kaiser. "Localization-delocalization transition in the dynamics of dipolar-coupled nuclear spins". Science 349, 846 (2015).

[2] Federico D. Dominguez, Maria Cristina Rodriguez, Robin Kaiser, Dieter Suter, Gonzalo A. lvarez. "Decoherence scaling transition in the dynamics of quantum information scrambling". arXiv:2005.12361 (2020).

See https://sites.google.com/view/pablopoggi/qchaos2020-seminars, where further information is provided, along with the actual streaming link.

9:00 am, Thursday, July 30, 2020
Zoom,

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