[LA-SiGMA-LSU] LASiGMA Seminar Friday, January 17th - Dr. Premala Chandra at 3:30 pm

[shelley lee]

Dear All,

Dr. Premala Chandra of the Rutgers University will be giving a seminar
Friday, January 17th at 3:30pm in 1008B at the Digital Media Center at the
Louisiana State University. The title of her talk is "Hastatic Order in
URu2Si2."

Abstract:
The development of collective long-range order by means of phase transitions
occurs by the spontaneous breaking of fundamental symmetries. Magnetism is a
consequence of broken-time reversal symmetry, whereas superfluidity results
from broken gauge invariance. The broken symmetry that develops below 17.5
kelvin in the heavy-fermion compound URu2Si2 has long eluded such
identification. In this talk I'll show that the recent observation of Ising
quasiparticles in URu2Si2 results from a spinor order parameter that breaks
double time-reversal symmetry, mixing states of integer and half-integer
spin. Such "hastatic" order hybridizes uranium-atom conduction electrons
with Ising 5f2 states to produce Ising quasiparticles; it accounts for the
large entropy of condensation and the magnetic anomaly observed in torque
magnetometry.  Hastatic order predicts a tiny transverse moment in the
conduction-electron "sea", a colossal Ising anisotropy in the nonlinear
susceptibility anomaly and a resonant, energy-dependent nematicity in the
tunnelling density of states.

This work was done in collaboration with P. Coleman and R. Flint (PC, P.
Coleman and R. Flint, Nature 493,
621 (2013)).

Biography:
Premala ("Premi") Chandra of Rutgers University in New Jersey is a
theoretical physicist who has worked in both academic and industrial
settings. Premi does "blue sky" research on problems inspired by
experimental puzzles observed in materials; her current interests include
microscopic and phenomenological studies of ferroelectrics, frustrated
magnetism and novel orderings in actinide materials.  In her applied work,
she has designed and patented a novel computer memory suitable for
high-density information storage and she is currently working on identifying
and characterizing dielectric/metallic nanostructures for specific
functionalities including energy harvesting.

Please see attached flyer and let me know if you have any questions.

Regards,

Shelley Lee

Project Coordinator

225-578-0465




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