Superresolution Microscopy of Cold Atoms in an Optical Lattice

Abstract

Super-resolution microscopy has revolutionized the fields of chemistry and biology by resolving features at the molecular level. Such techniques can be either "stochastic" [1], gaining resolution through precise localization of point source emitters, or "deterministic" [2,3], leveraging the nonlinear optical response of a sample to improve resolution. In atomic physics, deterministic methods can be applied to reveal the atomic wavefunction and to perform quantum control. Here we demonstrate super-resolution imaging based on nonlinear response of atoms to an optical pumping pulse. With this technique the atomic density distribution can be resolved with a point spread function FWHM of 32(4) nm and a localization precision below 1 nm. The short optical pumping pulse of 1.4 µs enables us to resolve fast atomic dynamics within a single lattice site. A byproduct of our scheme is the emergence of moiré patterns on the atomic cloud, which we show to be immensely magnified images of the atomic density in the lattice. Our work represents a general approach to accessing the physics of cold atoms at the nanometer scale, and can be extended to higher dimensional lattices and bulk systems for a variety of atomic and molecular species.

Quantum point spread function for imaging trapped few-body systems with a quantum gas microscope

“…However, it is a priori not clear, whether such a filter, which is independent of the underlying density, exists and if it does, how to obtain it. Yet, if one has found such a filter, equation (19) allows for applying established deconvolution algorithms for obtaining the pre-measurement density ρ(x). Making the most obvious choice by taking the diagonal of the qPSF, q(x)=Q(x, x), turns out to be numerically unstable and inaccurate.…”

“…Now that we know the filter q we can invert equation (19) for several unseen cases s(z) to obtain the pre-measurement density ρ(x). To this end a large toolbox of deconvolution algorithms exists, but these should be applied with care, since the problem is ill-posed and the best algorithm is usually determined by a comparative study.…”

“…Alternative schemes to reach sub-lattice resolution of quantum gases, inspired by related imaging techniques in other fields, have been proposed or realized. Stimulated emission depletion microscopy [16], which breaks the diffraction limit set by the imaging wavelength, can be adapted to quantum gases using the position-dependent dark state of a Lambda-system [17][18][19]. A scanning tunneling microscope could be realized by coupling to a single ion [20] or by using dispersive couplings to a cavity [21].…”

Charge and statistics of lattice quasiholes from density measurements: A tree tensor network study

“…Moreover, in order to provide a description which is as close as possible to experimentally realistic situations, we mainly focused our attention on systems with open boundary conditions (OBC) and mesoscopic numbers of particles. This makes our proposal to measure the anyonic statistics of FCI QHs readily applicable in state-of-the-art experiments with ultracold atoms and superconducting qubits, in which the HH model has already been implemented [60][61][62][63], and the occupation of the different lattice sites can be easily measured [62,[64][65][66][67].…”

Design and characterization of a quantum heat pump in a driven quantum gas

“…In this context the implementation and investigation of such devices with ultracold neutral atoms in tailored light-shift potentials defines a promising direction of research. Especially the recently developed quantum-gas microscopes, where digital mirror devices are employed for microstructuring almost arbitrary potential landscapes with high resolution both in space and time [7][8][9][10][11][12], provide an interesting platform for this goal. One advantage of atomic quantum gases in optical potentials is that they provide extremely clean conditions for studying the fundamental properties of quantum engines and pumps, since they do not suffer from dissipation induced by the coupling to phonons or due to radiative loss, as it is typically present in electronic systems.…”