Group seminar at MPQ and Zoom: Quantum simulation of many-body physics without error correction

Prof. Rahul Trivedi, University of Washington
Group seminar at MPQ lecture hall and Zoom
Tuesday, August 8, 09:00 am (MEZ)

Abstract:

Quantum devices offer a promising solution to the task of simulating many-body physics. A large-scale fault-tolerant quantum computer with a large supply of logical qubits would allow us to answer many interesting questions about physical systems. However, in the near term we can only access a limited number of noisy physical qubits, and thus cannot do full error correction. This has raised an important theoretical question of identifying both the limitations and power of near-term quantum hardware. In my talk, I will describe some of our recent work in identifying both complexity-theoretic and information-theoretic limitations imposed by noise on quantum advantage achievable by noisy quantum devices for simulating many-body physics. I will then also formalize a notion of quantum advantage in computing many-body order parameters using erroneous quantum simulators. I will then provide evidence that, within this framework, near-term quantum simulators without error correction could provide quantum advantage over the best known classical algorithms in simulating the physics of both gapped and gapless models arising in condensed matter physics.

References:

1.  R. Trivedi, J. I. Cirac, “Transitions in computational complexity of continuous-time local open quantum dynamics”, Phys. Rev. Lett 129 (26), 260405 (2022).
2.  G. Gonzalez*, R. Trivedi*, J. I. Cirac, “Error propagation in NISQ devices for solving classical optimization problems,” Phys. Rev. X Quantum 3 (4), 040326 (2022).
3.  R. Trivedi, A. F. Rubio, J. I. Cirac, “Quantum advantage and stability to errors in analogue quantum simulators,” arXiv:2212.04924 (2022).
4.  S. D. Mishra, M. Frias, R. Trivedi, “Classically computing performance bounds on depolarized quantum circuits,” arXiv:2306.16360 (2023).