Efficient Simulation of Loop Quantum Gravity: A Scalable Linear-Optical Approach

Cohen L, Brady AJ, Huang Z, Liu H, Qu D, Dowling JP, Han M (2021)

Publication Type: Journal article

Publication year: 2021

Journal

Physical Review Letters American Physical Society

Book Volume: 126

Article Number: 020501

Journal Issue: 2

DOI: 10.1103/PhysRevLett.126.020501

Abstract

The problem of simulating complex quantum processes on classical computers gave rise to the field of quantum simulations. Quantum simulators solve problems, such as boson sampling, where classical counterparts fail. In another field of physics, the unification of general relativity and quantum theory is one of the greatest challenges of our time. One leading approach is loop quantum gravity (LQG). Here, we connect these two fields and design a linear-optical simulator such that the evolution of the optical quantum gates simulates the spin-foam amplitudes of LQG. It has been shown that computing transition amplitudes in simple quantum field theories falls into the bounded-error quantum polynomial time class, which strongly suggests that computing transition amplitudes of LQG are classically intractable. Therefore, these amplitudes are efficiently computable with universal quantum computers, which are, alas, possibly decades away. We propose here an alternative special-purpose linear-optical quantum computer that can be implemented using current technologies. This machine is capable of efficiently computing these quantities. This work opens a new way to relate quantum gravity to quantum information and will expand our understanding of the theory.

Authors with CRIS profile

Muxin Han Chair for Theoretical Physics III (Quantum Gravity)

Involved external institutions

Fudan University / 复旦大学 CN China (CN) Louisiana State University US United States (USA) (US) Florida Atlantic University US United States (USA) (US) Peng Cheng Laboratory (PCL) CN China (CN)

How to cite

APA:

Cohen, L., Brady, A.J., Huang, Z., Liu, H., Qu, D., Dowling, J.P., & Han, M. (2021). Efficient Simulation of Loop Quantum Gravity: A Scalable Linear-Optical Approach. Physical Review Letters, 126(2). https://doi.org/10.1103/PhysRevLett.126.020501

MLA:

Cohen, Lior, et al. "Efficient Simulation of Loop Quantum Gravity: A Scalable Linear-Optical Approach." Physical Review Letters 126.2 (2021).

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