2012 Fall Graduate Colloquium Series: Meera Gurung/Dhurba Sapkota

DateOctober 26, 2012Time3:35 - 5:00 pm
LocationBaylor Sciences Building, Room E.125
Description
Meera Gurung

Frustrated Ordering

In general, an electron exhibits orbital and spin alignment. However, in some cases free electrons (e.g. metal-oxides (Ba3CuSb2O9)) localize near metal atoms as electron clouds. These electrons may occupy more than one type of orbital states of metals or may occupy different spin states. Under these conditions, together with structural changes, metal exhibits electron ordering, which strongly affects the spin and orbital character of the electronic state. At low temperature, under certain conditions, these spin and orbital states which carry magnetism can remain in liquid state. (Based on: L. Balents, Science 336, 547– 548 (2012)).

Dhurba Sapkota

Hall Effect in a Superfluid

In condensed-matter physics, many measurements techniques are based on Hall Effect. If the current flows perpendicular to a magnetic field, a Hall voltage develops in the direction transverse to both the current and the field. In semiconductors, this technique is used to measure the density and charge of the current carriers. The first observation of a Hall Effect in an ultra-cold gas of natural atoms is revealed by measuring a Bose-Einstein Condensate’s transport properties. Observations in Vortex-free superfluid are found in good agreement with hydrodynamic predictions showing the systems irrotationality which influences the Hall signal. (Based on L. J. LeBlanc, et al., Proc. Natl. Acad. Sci. USA 109, 10811-10814 (2012)).

For more information, please contact: Dr. Linda Olafsen 254-710-2541

PublisherDepartment of Physics
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