Coherent Atom Transport via Enhanced Shortcuts to Adiabaticity: Double-Well Optical Lattice

TL;DR

This paper explores advanced methods for fast, coherent atom transport in complex double-well optical lattices, demonstrating that enhanced shortcuts to adiabaticity outperform traditional methods, with implications for quantum computing and sensing.

Contribution

It introduces and compares enhanced shortcuts to adiabaticity (eSTA) with standard STA for atom transport in nonseparable 3D double-well optical lattices, showing improved efficiency.

Findings

eSTA outperforms STA in most lattice regimes

Transport fidelity is significantly improved with eSTA

The methods are applicable to quantum computing and sensing

Abstract

Theoretical studies of coherent atom transport have as yet mainly been restricted to one-dimensional model systems with harmonic trapping potentials. Here we investigate this important phenomenon -- a prerequisite for a variety of quantum-technology applications based on cold neutral atoms -- under much more complex physical circumstances. More specificially yet, we study fast atomic transport in a moving {\em double-well optical lattice}, whose three-dimensional (anharmonic) potential is nonseparable in the $x-y$ plane. We first propose specific configurations of acousto-optic modulators that give rise to the moving-lattice effect in an arbitrary direction in this plane. We then determine moving-lattice trajectories that enable single-atom transport using two classes of quantum-control methods: shortcuts to adiabaticity (STA), here utilized in the form of inverse engineering based on a quadratic-in-momentum dynamical invariant of Lewis-Riesenfeld type, and their recently proposed modification termed enhanced STA (eSTA). Subsequently, we quantify the resulting single-atom dynamics by numerically solving the relevant time-dependent Schr\"{o}dinger equations and compare the efficiency of STA- and eSTA-based transport by evaluating the respective fidelities. We show that -- except for the regime of shallow lattices -- the eSTA method consistently outperforms its STA counterpart. This study has direct implications for neutral-atom quantum computing based on collisional entangling two-qubit gates and quantum sensing of constant homogeneous forces via guided-atom interferometry.