Fast initialization of a high-fidelity quantum register using optical superlattices

TL;DR

This paper introduces a rapid method to initialize a high-fidelity quantum register of ultracold atoms in an optical lattice by using superlattice potentials to double the lattice periodicity, enabling faster qubit preparation.

Contribution

It presents a novel approach combining superlattice potentials and numerical analysis to significantly speed up quantum register initialization compared to traditional methods.

Findings

The process is faster than direct adiabatic freezing for large lattices.

The method achieves high fidelity in a shorter time.

Numerical and analytical models confirm the efficiency of the approach.

Abstract

We propose a method for the fast generation of a quantum register of addressable qubits consisting of ultracold atoms stored in an optical lattice. Starting with a half filled lattice we remove every second lattice barrier by adiabatically switching on a superlattice potential which leads to a long wavelength lattice in the Mott insulator state with unit filling. The larger periodicity of the resulting lattice could make individual addressing of the atoms via an external laser feasible. We develop a Bose-Hubbard-like model for describing the dynamics of cold atoms in a lattice when doubling the lattice periodicity via the addition of a superlattice potential. The dynamics of the transition from a half filled to a commensurately filled lattice is analyzed numerically with the help of the Time Evolving Block Decimation algorithm and analytically using the Kibble-Zurek theory. We show that the time scale for the whole process, i.e. creating the half filled lattice and subsequent doubling of the lattice periodicity, is significantly faster than adiabatic direct quantum freezing of a superfluid into a Mott insulator for large lattice periods. Our method therefore provides a high fidelity quantum register of addressable qubits on a fast time scale.