Computational Multiqubit Tunnelling in Programmable Quantum Annealers

Quantum tunnelling is a phenomenon in which a quantum state traverses energy barriers higher than the energy of the state itself. Quantum tunnelling has been hypothesized as an advantageous physical resource for optimization in quantum annealing. However, computational multiqubit tunnelling has not...

Full description

Saved in:
Bibliographic Details
Main Authors: Boxio,Sergio, Smelyanskiy,Vadim N, Shabani,Alireza, Isakov,Sergei V, Dykman,Mark, Denchev,Vasil S, Amin,Mohammad H, Smirnov,Anatoly Y, Mohseni,Masoud, Neven,Hartmut
Format: Report
Language:English
Subjects:
annealing
Applied physics
couplings
energy
fittings
freezing
frequency
ground state
optimization
Physical sciences
probability
QUANTUM BITS
Theoretical physics
transitions
Online Access:Request full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Quantum tunnelling is a phenomenon in which a quantum state traverses energy barriers higher than the energy of the state itself. Quantum tunnelling has been hypothesized as an advantageous physical resource for optimization in quantum annealing. However, computational multiqubit tunnelling has not yet been observed, and a theory of co-tunneling under high- and low-frequency noises is lacking. Here we show that 8-qubit tunnelling plays a computational role in a currently available programmable quantum annealer. We devise a probe for tunnelling, a computational primitive where classical paths are trapped in a false minimum. In support of the design of quantum annealers we develop a nonperturbative theory of open quantum dynamics under realistic noise characteristics. This theory accurately predicts the rate of many-body dissipative quantum tunnelling subject to the polaron effect. Furthermore, we experimentally demonstrate that quantum tunnelling outperforms thermal hopping along classical paths for problems with up to 200 qubits containing the computational primitive. Nature Communications , 7, 01 Jan 0001, 01 Jan 0001, Open Access: Publishers Version. May be placed on public websites; Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/).