Special 290S/290K Quantum Materials Seminar speaker Thomas Scaffidi (UC Irvine) Tuesday, December 6 at 2 pm in 402 Physics South

Time/Venue Tuesday, December 6 at 2:00 pm Pacific Time in Physics South 402 and via Zoom:

Meeting ID: 995 2349 9113 Passcode: 600704
Host Ehud Altman
Title Spread and erase — How electron hydrodynamics can eliminate the
Landauer-Sharvin resistance
Abstract What is the ultimate limit of conductance of a metallic device of
lateral size W? In the ballistic limit, the answer is the
Landauer-Sharvin conductance, which is associated with an abrupt
reduction of the number of conducting channels when going from the
contacts to the device. However, the ballistic limit is not always the
best-case scenario, since adding strong electron-electron scattering can
take electrons to a viscous regime of transport for which
“super-ballistic” flows were recently studied. In this talk, we will
show that by a proper choice of geometry which resembles a “wormhole”,
it is possible to spread the Landauer-Sharvin resistance throughout the
bulk of the system, allowing its complete elimination by electron
hydrodynamics. This effect arises due to the interplay between geometry
and strong electron-electron scattering, which allows for a net transfer
of carriers from reflected to transmitted channels. Finally, we will
discuss a recent experiment in a Corbino geometry which realizes one
half of this “wormhole” geometry


Theory: Phys. Rev. Lett. 129, 157701 (2022)

Experiment: Nature 609, 276–281 (2022)

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