Many-particle confinement by constructed disorder and quantum computing

TL;DR

This paper demonstrates a method to achieve many-particle confinement in a 1D quantum system using constructed disorder, supporting the feasibility of time-independent qubit coupling in quantum computing.

Contribution

It introduces a bounded sequence of site energies that induces strong many-particle confinement, advancing quantum computing with static qubit interactions.

Findings

Single-particle confinement achieved for all states.

Many-particle confinement persists for a high power of inverse hopping.

Confinement occurs with strong interactions and small bandwidth.

Abstract

Many-particle confinement (localization) is studied for a 1D system of spinless fermions with nearest-neighbor hopping and interaction, or equivalently, for an anisotropic Heisenberg spin-1/2 chain. This system is frequently used to model quantum computers with perpetually coupled qubits. We construct a bounded sequence of site energies that leads to strong single-particle confinement of all states on individual sites. We show that this sequence also leads to a confinement of all many-particle states in an infinite system for a time that scales as a high power of the reciprocal hopping integral. The confinement is achieved for strong interaction between the particles while keeping the overall bandwidth of site energies comparatively small. The results show viability of quantum computing with time-independent qubit coupling.