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.


Perpetual emulation threshold of PT-symmetric Hamiltonians

We describe a technique to emulate the dynamics of two-level PT-symmetric spin Hamiltonians, replete with gain and loss, using the unitary dynamics of a larger quantum system. The two-level system in question is embedded in a subspace of a four-level

Second Chern number of a quantum-simulated non-Abelian Yang monopole

Topological order is often quantified in terms of Chern numbers, each of which classifies a topological singularity. Here, inspired by concepts from high-energy physics, we use quantum simulation based on the spin degrees of freedom of atomic Bose-Einstein condensates to

Topological lattice using multi-frequency radiation

We describe a novel technique for creating an artificial magnetic field for ultracold atoms using a periodically pulsed pair of counter propagating Raman lasers that drive transitions between a pair of internal atomic spin states: a multi-frequency coupling term. In

Eliot Fenton: a UMD Undergraduate Researchers of the Year for 2018

UMD Senior Eliot Fenton (LEFT FRONT) was been selected for recognition as one of Maryland¹s ‘Undergraduate Researchers of the Year’ for 2018. So cool! After the awards ceremony we all went to town hall to celebrate! Eliot will be moving

A Rapidly Expanding Bose-Einstein Condensate: An Expanding Universe in the Lab

We study the dynamics of a supersonically expanding, ring-shaped Bose-Einstein condensate both experimentally and theoretically. The expansion redshifts long-wavelength excitations, as in an expanding universe. After expansion, energy in the radial mode leads to the production of bulk topological excitations—solitons

ErNa Photo-op!

Pictured is the ErNa team: from left to right: Hector Sosa Martinez (Postdoc), Ian B. Spielman (collaborator), Gretchen K. Campbell (PI),  Avinash Kumar (pre-h. D), Madison Anderson (graduate student), Monica Gutierrez Galan (graduate student), and Swarnav Banik (graduate student).

Synthetic clock transitions via continuous dynamical decoupling

Decoherence of quantum systems due to uncontrolled fluctuations of the environment presents fundamental obstacles in quantum science. Clock transitions which are insensitive to such fluctuations are used to improve coherence, however, they are not present in all systems or for

Russell Anderson returns to his native land

After a very productive two month visit to the RbL lab at JQI, Russell Anderson of Monash University has returned home.  Thanks for a great time Russ!

Quantum phases of two-component bosons with spin-orbit coupling in optical lattices

Ultracold bosons in optical lattices are one of the few systems where bosonic matter is known to exhibit strong correlations. Here we push the frontier of our understanding of interacting bosons in optical lattices by adding synthetic spin-orbit coupling, and

Andkia Putra Ph.D. defends his thesis

On this the 17th of November, 2017, Andika Putra defended his thesis to be elevated to the status of Doctor of Philosophy. Congratulations Dr. Putra!