A regular Hamiltonian halting ratchet for matter wave transport

TL;DR

This paper introduces a Hamiltonian ratchet mechanism enabling linear, non-diffusive matter wave transport in a modulated optical lattice, with experimental validation using Bose-Einstein condensates and quantum control techniques.

Contribution

It presents a novel Hamiltonian ratchet design exploiting phase space trajectories, with experimental observation and quantum control methods to enhance transport efficiency.

Findings

First experimental observation of the spatial ratchet transport.

Transport depends on the effective Planck constant due to Floquet state mixing.

Quantum optimal control improves initial state preparation and transport periodicity.

Abstract

We report on the design of a Hamiltonian ratchet exploiting periodically at rest integrable trajectories in the phase space of a modulated periodic potential, leading to the linear non-diffusive transport of particles. Using Bose-Einstein condensates in a modulated one-dimensional optical lattice, we make the first observations of this new spatial ratchet transport. In the semiclassical regime, the quantum transport strongly depends on the effective Planck constant due to Floquet state mixing. We also demonstrate the interest of quantum optimal control for efficient initial state preparation into the transporting Floquet states to enhance the transport periodicity.