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CALSCALE:GREGORIAN
PRODID:UW-Madison-Physics-Events
BEGIN:VEVENT
SEQUENCE:2
UID:UW-Physics-Event-9312
DTSTART:20250925T150000Z
DTEND:20250925T230000Z
DTSTAMP:20260413T084146Z
LAST-MODIFIED:20250916T154249Z
LOCATION:5310 Chamberlin
SUMMARY:Manipulating Valley Degree of Freedom via Nano-gating and Twis
t\, R. G. Herb Condensed Matter Seminar\, Ke Wang\, UMN
DESCRIPTION:Within condensed matter physics\, the study of two-dimensi
onal (2D) systems is a diverse and active field of interest with a ric
h history. High-quality two-dimensional electron gases (2DEG) in GaAs/
AlGaAs heterostructures have enabled the discovery of rich quantum Hal
l physics. With the help of electron-beam-defined nano gates\, system
dimensions can be further reduced to be mesoscopic and comparable to t
he electron wavelength. In such gate-defined nanostructures\, novel qu
antum phases can be locally defined and coherently manipulated to real
ize quantum bits and quantum interferometers\, providing versatile exp
erimental platforms to answer many key questions in condensed matter p
hysics.
\n
\nSince the discovery of graphene via mechanical exf
oliation\, it has been shown that the electronic properties of solids
can undergo dramatic changes when the material thickness is reduced to
the atomic limit. Moreover\, the properties of the 2D materials can b
e further tailored by stacking them with relative twist angles. Combin
ing this designer material platform with the gate-defined nanostructur
es\, the highly tunable local Hamiltonian allows a local probe to the
rich underlying physics and a platform to study new mesoscopic quantum
phenomena. In this talk\, I will discuss our recent experiments in tu
ning valley-specific Berry curvature and band topology in bilayer grap
hene via gate-defined nanostructures and twist\, towards investigating
novel mesoscopic quantum physics and demonstrating new quantum device
concepts.
\n
URL:https://www.physics.wisc.edu/events/?id=9312
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