Measurement. Science is rooted in measurement: it is from measurements, as unified by theory, that understanding is born. Our comprehension of the universe is therefore bounded by our ability to observe and shaped by human creativity.  Scientific progress is driven by the identification of new physical systems and measurement techniques, leading to new conceptual understanding. Our experiments use systems of ultracold neutral atoms, quantum gases, that make quantum physics manifest in the laboratory. Many properties of these systems can be understood in the intellectual context of many-body physics which describes systems from the commonplace such as crystals, fluids, and semiconductors, to the extreme such as superconductors, quantum Hall systems, and neutron stars.  Many-body physics asks how the properties of individual components — atoms, electrons, nucleons — give rise to the observed macroscopic phenomena.

Ultracold atoms are a very different sort of system than conventional materials, composed of a few hundred to a few hundred million atoms, with densities ranging from 1012 cm-3 to 1015 cm-3, and at temperatures from below 1 nK to a couple uK.  These atomic systems are unique in the simplicity of their underlying Hamiltonian along with a singular capacity for controlling and engineering their quantum degrees of freedom.

Our experiments — inspired by the on-going theory efforts of our collaborators world-wide — take place on three distinct apparatuses: RbK, focusing on artificial gauge fields for atomic Bose and Fermi gases; RbChip, creating spin-dependent forces without light; and RbLi, designing long range interactions mediated by particle exchange.

Dr. Lauren M. Aycock defended her thesis today.


Lauren defended her thesis titled “Topological excitations in a Bose gas & sexual harassment reported by undergraduate physicists” today to a bumper audience in Ithaca.  And it rocked!

Posted in Group News, Personnel, RbK, Uncategorized

Tutorial: Synthetic gauge potentials for ultracold neutral atoms


Synthetic gauge fields for ultracold neutral atoms—engineered using the interaction between laser fields and the atoms’ internal ‘spin’ degrees of freedom—provide promising techniques for generating the large (synthetic) magnetic fields required to reach the fractional quantum Hall (FQH) limit in

Posted in Group News, Papers Published, RbK, Theory

Geometrical Pumping with a Bose-Einstein Condensate


We realized a quantum geometric “charge” pump for a Bose-Einstein condensate (BEC) in the lowest Bloch band of a novel bipartite magnetic lattice [JQI writeup]. Topological charge pumps in filled bands yield quantized pumping set by the global—topological—properties of the

Posted in Atomtronics, Group News, Papers Published, RbK

Rockville Science day with Troop 1097


The boys of Boy Scout troop 1097 helped Ian out and presented experiments ranging from magnetism to superconductivity at the 2016 Rockville Science day! In the photo, Michael and Camden are explaining an electromagnet and induced currents!

Posted in Group News

Celebration of: Magnetic phases of spin-1 spin–orbit-coupled Bose gases


The UMD team got together to celebrate our recent paper “Magnetic phases of spin-1 spin–orbit-coupled Bose gases;” for some reason we went to Town Hall a long-time College Park dive bar. Times were good! Ana, Erin and Dimi were in

Posted in Group News, RbLi

Original BEC Experiment in Gaithersburg: Vented!


The first Na BEC experiment in Gaithersburg was vented today.  This experiment has lead a long and happy life, first creating a Na BEC in 1998, then studying solitons, optical lattices, four-wave mixing, and more recently looking at atoms in

Posted in Group News

Rashba realization: Raman with RF


We theoretically explore a Rashba spin–orbit coupling scheme which operates entirely in the absolute ground state manifold of an alkali atom, thereby minimizing all inelastic processes. An energy gap between ground eigenstates of the proposed coupling can be continuously opened

Posted in Atomtronics, Group News, Papers Published, RbLi

Magnetic phases of spin-1 spin–orbit-coupled Bose gases


Phases of matter are characterized by order parameters describing the type and degree of order in a system. Here we experimentally explore the magnetic phases present in a near-zero temperature spin-1 spin–orbit-coupled atomic Bose gas and the quantum phase transitions

Posted in Atomtronics, Group News, Papers Published, RbLi, Uncategorized

Interaction-driven exotic quantum phases in spin-orbit-coupled spin-1 bosons


We study the interplay between large-spin, spin-orbit coupling, and superfluidity for bosons in a two-dimensional optical lattice, focusing on the spin-1 spin-orbit-coupled system recently realized at the Joint Quantum Institute [Campbell et al., arXiv:1501.05984]. We find a rich quantum phase

Posted in Atomtronics, Group News, Papers Published, Theory

Feshbach enhanced s-wave scattering of fermions: direct observation with optimized absorption imaging


We directly measured the normalized s-wave scattering cross-section of ultracold 40K atoms across a magnetic-field Feshbach resonance by colliding pairs of degenerate Fermi gases (DFGs) and imaging the scattered atoms. We extracted the scattered fraction for a range of bias

Posted in Atomtronics, Group News, Papers Published, RbK