Stroboscopic painting of optical potentials for atoms with subwavelength resolution

Abstract

We propose and discuss a method to engineer stroboscopically arbitrary one-dimensional optical potentials with subwavelength resolution. Our approach is based on subwavelength optical potential barriers for atoms in the dark state in an optical Λsystem, which we use as a stroboscopic drawing tool by controlling their amplitude and position by changing the amplitude and the phase of the control Rabi frequency in the Λsystem. We demonstrate the ability of the method to engineer both smooth and comb-like periodic potentials for atoms in the dark state, and establish the range of stroboscopic frequencies when the quasienergies of the stroboscopic Floquet system reproduce the band structure of the time-averaged potentials. In contrast to usual stroboscopic engineering which becomes increasingly accurate with increasing the stroboscopic frequency, the presence of the bright states of the Λ-system results in the upper bound on the frequency, above which the dynamics strongly mixes the dark and the bright channels, and the description in terms of a time-averaged potential fails. For frequencies below this bound, the lowest Bloch band of quasienergies contains several avoided-crossing coming from the coupling to high energy states, with widths decreasing with increasing stroboscopic frequency. We analyze the influence of these avoided crossings on the dynamics in the lowest band using Bloch oscillations as an example, and establish the parameter regimes when the population transfer from the lowest band into high bands is negligible. We also present protocols for loading atoms into the lowest band of the painted potentials starting from atoms in the lowest band of a standard optical lattice.

14 pages, 9 figures

References in corpus (8)

• Many-Body Physics with Ultracold Gases
• Periodically-driven quantum systems: Effective Hamiltonians and engineered gauge fields
• Dark state optical lattice with sub-wavelength spatial structure
• Nano-Scale `Dark State' Optical Potentials for Cold Atoms
• State-dependent, addressable subwavelength lattices with cold atoms
• Subwavelength-width optical tunnel junctions for ultracold atoms
• Bloch oscillations of atoms in an optical multiphoton potential
• Observations of $\lambda /4$ structure in a low-loss radiofrequency-dressed optical lattice

Cited by in corpus (14)

• Dipolar physics: A review of experiments with magnetic quantum gases
• Realization of a stroboscopic optical lattice for cold atoms with subwavelength spacing
• Precise Programmable Quantum Simulations with Optical Lattices
• Quantum Many-Body Physics with Ultracold Polar Molecules: Nanostructured Potential Barriers and Interactions
• Super-resolved imaging of a single cold atom on a nanosecond timescale
• Coherent optical nano-tweezers for ultra-cold atoms
• Dark-State Optical Potential Barriers with Nanoscale Spacing
• A dark state of Chern bands: Designing flat bands with higher Chern number
• Radiative toroidal dipole and anapole excitations in collectively responding arrays of atoms
• Floquet engineering of optical lattices with spatial features and periodicity below the diffraction limit
• Programmable Hamiltonian engineering with quadratic quantum Fourier transform
• Random Kronig-Penney-type potentials for ultracold atoms using dark states
• Emergent topological properties in spatially modulated sub-wavelength barrier lattices
• $p$-band stability of ultracold atom gas in anharmonic optical lattice potential with large energy scales