1 research outputs found
Digital quantum simulation of scalar Yukawa coupling: Dynamics following an interaction quench on IBM Q
Motivated by the dearth of studies pertaining to the digital quantum
simulation of coupled fermion-boson systems and the revitalized interest in
simulating models from medium- and high-energy physics, we investigate the
nonequilibrium dynamics following a Yukawa-interaction quench on IBM Q. After
adopting -- due to current quantum-hardware limitations -- a single-site
(zero-dimensional) version of the scalar Yukawa-coupling model as our point of
departure, we design low-depth quantum circuits that emulate its dynamics with
up to three bosons. In particular, using advanced circuit-optimization
techniques, in the one-boson case we demonstrate circuit compression, i.e.
design a shallow (constant-depth) circuit that contains only two CNOT gates,
regardless of the total simulation time. In the three-boson case -- where such
a compression is not possible -- we design a circuit in which one Trotter step
entails 8 CNOTs, this number being far below the maximal CNOT-cost of a generic
three-qubit gate. Using an analogy with the travelling salesman problem, we
also provide a CNOT-cost estimate for quantum circuits emulating the system
dynamics for higher boson-number truncations. Finally, based on the proposed
circuits for one- and three-boson cases, we quantify the system dynamics for
several different initial states by evaluating the expected fermion- and boson
numbers at an arbitrary time after the quench. We validate our results by
finding their good agreement with the exact ones obtained through classical
benchmarking.Comment: 19 pages, 21 figure