A Single Atom Mirror for 1D Atomic Lattice Gases

TL;DR

This paper introduces a quantum interference scheme using a single impurity atom in a 1D optical lattice to control atomic transport, enabling quantum measurement and potential quantum information applications.

Contribution

It presents an exact analytical model for atom scattering and demonstrates how a single impurity can act as a quantum switch or mirror in a 1D lattice.

Findings

Impurity atom can switch between transparent and reflective states for lattice gases.

Exact scattering expressions derived for single atom interactions.

Approximate dynamics described for many interacting bosonic and fermionic atoms.

Abstract

We propose a scheme utilizing quantum interference to control the transport of atoms in a 1D optical lattice by a single impurity atom. The two internal state of the impurity represent a spin-1/2 (qubit), which in one spin state is perfectly transparent to the lattice gas, and in the other spin state acts as a single atom mirror, confining the lattice gas. This allows to ``amplify'' the state of the qubit, and provides a single-shot quantum non-demolition measurement of the state of the qubit. We derive exact analytical expression for the scattering of a single atom by the impurity, and give approximate expressions for the dynamics a gas of many interacting bosonic of fermionic atoms.