Research Seminars @ Illinois

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Tailored for undergraduate researchers, this calendar is a curated list of research seminars at the University of Illinois. Explore the diverse world of research and expand your knowledge through engaging sessions designed to inspire and enlighten.

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The Anthony J Leggett Institute for Condensed Matter Physics Special Seminar: "Theory of Coulomb driven nematicity in a multi-valley two-dimensional electron gas"

Event Type
Seminar/Symposium
Sponsor
Physics Department
Location
ESB 190
Date
Nov 14, 2024   11:00 am  
Speaker
Erez Berg, Weizmann Institute of Science
Contact
Ljubica Milutinovic
E-Mail
ljubicam@illinois.edu
Phone
217-300-6393
Views
44
Originating Calendar
Physics - The Anthony J Leggett Institute for Condensed Matter Theory Seminar

The properties of a two-dimensional electron gas (2DEG) in a semiconductor host with two valleys related by an underlying C4 rotational symmetry are studied using Hartree-Fock (HF) and various other many-body approaches. A familiar artifact of the HF approach is a degeneracy between the valley polarized - ``Ising nematic'' - and spin polarized - ferromagnetic - phases, which is inconsistent with recent variational Monte Carlo (VMC) results. Correlation effects, computed either within the random phase approximation (RPA) or the T-matrix approximation, enhance the valley susceptibility relative to the spin susceptibility. Extrapolating the results to finite interaction strength, we find a direct first-order transition from a symmetry-unbroken state to a spin unpolarized Ising nematic fluid with full valley polarization, in qualitative agreement with VMC. The RPA results are also reminiscent of experiments on the corresponding 2DEG in AlAs heterostructures.

 

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