Coherent shift of localized bound pair in Bose Hubbard model

TL;DR

This paper demonstrates the existence of stable bound pair wave packets in the Bose Hubbard model and shows how they can be used to create a quantum switch for controlling photon transport.

Contribution

It provides exact Bethe ansatz results showing coherent shifts of bound pairs, proposing a new scheme for a BP charge qubit in quantum information processing.

Findings

Stable bound pair wave packets exist in Bose Hubbard model.

Single particles can coherently pass through bound pairs with a positional shift.

Proposed scheme for a quantum switch using bound pairs.

Abstract

Based on the exact results obtained by Bethe ansatz, we demonstrate the existence of stable bound pair (BP) wave packet in Bose Hubbard model with arbitrary on-site interaction U. In large-U regime, it is found that an incoming single-particle (SP) can coherently pass through a BP wave packet and leave a coherent shift in the position of it. This suggests a simple scheme for constructing a BP charge qubit to realize a quantum switch, which is capable of controlling the coherent transport of one and only one photon in a one-dimensional waveguide.