Items tagged with "BEC"
Physicists use theoretical and experimental techniques to develop explanations of the goings-on in nature. Somewhat surprisingly, many phenomena such as electrical conduction can be explained through relatively simplified mathematical pictures — models that were constructed well before the advent of modern computation. And then there are things in nature that push even the limits of high performance computing and sophisticated experimental tools.
Quantum computers will someday perform calculations impossible for conventional digital computers. But for that to happen, the core quantum information must be preserved against contamination from the environment. In other words, decoherence of qubits must be forestalled. Coherence, the ability of a system to retain quantum integrity---meaning that one part of the system can be used to predict the behavior of other parts---is an important consideration.
JQI scientists have added an important technique to the atomtronics arsenal, a method for analyzing a superfluid circuit component called a ‘weak link’. The result, detailed in the online journal Physical Review X, is the first direct measurement of the current-phase relationship of a weak link in a cold atom system.
JQI physicists report detailed calculations of the dynamics of a positronium BEC. This work is the first to account for effects of collisions between different positronium species. These collisions put important constraints on gamma-ray laser operation.
Atomtronics is an emerging technology whereby physicists use ensembles of atoms to build analogs to electronic circuit elements. Modern electronics relies on utilizing the charge properties of the electron. Using lasers and magnetic fields, atomic systems can be engineered to have behavior analogous to that of electrons, making them an exciting platform for studying and generating alternatives to charge-based electronics. Read more to learn more about recent atomtronics research.
Atomtronics is an emerging technology whereby physicists use ensembles of atoms to build analogs to electronic circuit elements. Modern electronics relies on utilizing the charge properties of the electron. Using lasers and magnetic fields, atomic systems can be engineered to have behavior analogous to that of electrons, making them an exciting platform for studying and generating alternatives to charge-based electronics.
Gretchen Campbell’s UMD laboratory has reached an important milestone in their experiment: a strontium Bose-Einstein condensate (BEC). This brings the total number of ultracold quantum gases at JQI to 10. These experiments study a rich variety of topics, from quantum information to many-body physics. Campbell's lab is the third in the world to condense strontium into a quantum state. Read more to learn more about these pristine quantum gases.
Vortices pop-up in the weather, sink drains, and even astrophysics; they also occur in superfluids, such as an ultracold atomic gas. The circulation in these systems obeys certain quantization criteria. When a superfluid is disturbed vortices will form in order to satisfy this circulation constraint. Vortices look like mini-tornados, having an essentially empty core or “eye." Stirring up a superfluid is one way to induce vortices. Introducing spin-orbit coupling can also do this. Another cool aspect: in seeking out the lowest energy configuration, the vortices will arrange into a lattice. Read more to learn more about core-less vortices—a quantum storm without an ‘eye.’
JQI researchers perform a quantum simulation of the 1D Dirac equation, by assembling an analogue system of neutral atoms in a Bose-Einstein condensate.