CME Seminar (Tomorrow) - Andrei Kogan, U Cincinnati, Thursday April 21, 11:30 am, Smith Seminar Room

[Roland Kawakami]

Please join us on Thursday, April 21st at 11:30am for the Condensed Matter
Experiment Seminar presented by Andrei Kogan in room 1080PRB Smith Seminar
Room.

Title :
Non-Adiabatic Transport in Single-Electron Transistors in the Kondo Regime

Andrei Kogan
Department of Physics
University of Cincinnati

Abstract:

Magnetic impurities in  conductors alter the Fermi sea: A many-body state
(A Kondo singlet) is formed that entangles itinerant carriers and the
impurity site. This causes a sharp rearrangement of the density of states
near the Fermi surface  into a  hierarchical set governed by a single
energy parameter Tk,  the Kondo temperature. Equilibrium physics of such
electronic “knots” scales with Tk and is highly universal: impurities that
differ microscopically from one another yet have similar Kondo temperatures
produce Kondo states with similar properties. Recent studies of Kondo
physics with  voltage-controllable spin traps known as Single-Electron
Transistors (SETs) have focused on nonequiibrium Kondo phenomena, sensitive
to the interplay between coherent correlations and dissipative effects,
aiming to understand the extent of Kondo universality away from equilibrium.

In this talk, I will give a brief overview of experimental work on
nonequillibrium Kondo physics and present our  transport measurements in
SETs with microwave-frequency modulation. We observe an  onset of
nonadiabatic effects in conductance at frequencies comparable to the Kondo
temperature, which suggest that the Kondo temperature may define a
universal scale for dynamic phenomena. We also compare the results to
theoretical predictions for the universal spin decoherence rate in Kondo
systems.

-- 
----------
Roland Kawakami
Department of Physics
The Ohio State University
(614) 271-3749
----------
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osu.edu/pipermail/physics-staff-df/attachments/20160420/1cbb7bf9/attachment.html>