Microwave preparation of two-dimensional fermionic spin mixtures

Abstract

We present a method for preparing a single two-dimensional sample of a two-spin mixture of fermionic potassium in a single antinode of an optical lattice, in a quantum-gas microscope apparatus. Our technique relies on spatially-selective microwave transitions in a magnetic field gradient. Adiabatic transfer pulses were optimized for high efficiency and minimal atom loss and heating due to spin-changing collisions. We have measured the dynamics of those loss processes, which are more pronounced in the presence of a spin mixture. As the efficient preparation of atoms in a single antinode requires a homogeneous transverse magnetic field, we developed a method to image and minimize the magnetic field gradients in the focal plane of the microscope.

Generating two-dimensional quantum gases with high stability*

“…The rest atoms which are not selected will be blown away from the system by a resonant laser beam. [3,4,6,15,16] In order to perform future experiments with a prepared 2D system, repeatedly producing the 2D system with high stability is of key importance. This would ensure the highfidelity manipulation of many-body quantum state and a sufficient signal-to-noise ratio (SNR) during imaging.…”

“…A repeated measurement on the spatial drift of the flipped atoms calibrates the drift of the magnetic field as 0.042(3) mG/hour, which outperforms the best results reported in a couple similar experiments. [16,21] In the following, we describe the experimental setup in Section 2. The overview on preparing the 2D quantum system is present in Section 3.…”

Cold-atom shaping with MEMS scanning mirrors

“…The technique could be extended to dynamic beam shuttering. More dynamic control of the scan amplitude and phase would make it possible to form more complex geometries opening the technique to more applications such as the storing of images for quantum information processing [29], selection of individual layers of optical lattices [30], generation of arbitrary geometry matterwave circuits [31], and all-optical adaptable atomtronics [32] Funding. Defence Science and Technology Laboratory; Royal Academy of Engineering (RF/202021/20/343, RF1516/15/8); Engineering and Physical Sciences Research Council (EP/S032606/1, EP/T001046/1).…”