Quantum magnetism with highly magnetic atoms

Andrei Derevianko, Caleb C. Cannon

Jennie Guzman, Sabrina R. Leslie, Mukund Vengalattore +2 more

Ziji Wang, Junming Wu, Gong Sun +1 more

A monolithically integrated 3D atomic chip for weak magnetic field detection is presented in this work. A 14.8 ohm MEMS thin film non-magnetic micro heater is monolithically integrated onto a micro spherical alkali vapor cell to realize on-chip atomic density control. Both magnetic and thermal characteristics of the non-magnetic heater are analyzed theoretically. Based on the heater-integrated atomic chip, a chip-scale scalar atomic magnetometer is realized and tested in a magnetic shield. Effect of heating noise suppression methods including high frequency heating, noise-shifting heating and high precision feedback control on magnetometer performance is experimentally analyzed. By further analyzing and eliminating glitch noise in output signal, magnetic noise floor of the constructed device reduced by over 88 %. The proposed atomic chip is especially advantageous for future low-cost and high integration quantum optical magnetometry. [2023-0152]

Ulrich Schollwöck, Johannes Richter, DAMIAN J. J. FARNELL +1 more

I. Herrera, Y. Wang, Pierrette Michaux +8 more

Abstract We report on the design, fabrication and characterization of magnetic nanostructures to create a lattice of magnetic traps with sub-micron period for trapping ultracold atoms. These magnetic nanostructures were fabricated by patterning a Co/Pd multilayered magnetic film grown on a silicon substrate using high precision e-beam lithography and reactive ion etching. The Co/Pd film was chosen for its small grain size and high remanent magnetization and coercivity. The fabricated structures are designed to magnetically trap 87 Rb atoms above the surface of the magnetic film with one-dimensional and two-dimensional (triangular and square) lattice geometries and sub-micron period. Such magnetic lattices can be used for quantum tunneling and quantum simulation experiments, including using geometries and periods that may be inaccessible with optical lattices.

Éric Paradis

In this thesis I examine high-magnetic-field Rydberg spectra, with the goal of discerning the viability of using such states as an interaction mechanism for quantum computation processes. In the presence of a strong magnetic field of B0 = 2.6 T, high-lying states of E ~ -55 cm(-1) are non-degenerate and show a wide range of magnetic dipole moments. Near-degenerate pairs of states of the same mJ manifold but of different axial parity Pi_z will strongly interact in the presence of an applied weak parallel electric field F, generating a pair of highly polar states. I show experimental results that, in agreement with theoretical work presented here, illustrate the presence of strong permanent dipole moments p ~ 1500 ea0 under these conditions. Such Rydberg states can also be tuned into resonance through careful control of the magnetic field, and are suitable for developing quantum phase gates and performing Rydberg-Rydberg interaction experiments. In order to perform such high-field Rydberg excitation experiments, a stable, dense and well-controlled cold atom cloud is needed within a high-magnetic-field environment. Toward this end, I present a full characterization of the utilized high-field trapping apparatus, including measurements of the trapped atom sample size, shape, and temperature. Analysis of the loss rate from the high-magnetic-field atom trap, both as a function of the applied magnetic field B0 and transverse confinement are presented. Experimental results for the high-field confinement of 85Rb are presented, as well as the first demonstration of a high-field 87Rb trap. Current trap limitations and possible improvements to the trapping apparatus are discussed. Other applications of the high-magnetic-field trap, such as the investigation of ultracold two-component plasmas and three-body recombination experiments, are also presented.