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TZID:Europe/Paris
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BEGIN:VEVENT
UID:0-578@lptms.universite-paris-saclay.fr
DTSTART:20180329T110000Z
DTEND:20180329T113000Z
DTSTAMP:20180313T213416Z
URL:https://www.lptms.universite-paris-saclay.fr/seminars/seminaire-du-lpt
 ms-alexandru-petrescu-seminaire-exceptionnel/
SUMMARY:Séminaire du LPTMS: Michele Filippone  *** séminaire exceptionnel
  *** - LPTMS\, salle 201\, 2ème étage\, Bât 100\, Campus d'Orsay - 29 M
 ar 18 11:00
DESCRIPTION:Controlled Parity Switch of Persistent Currents and Topological
  charge-pumping effects induced by bulk magnetic fluxes\n\nMichele Filippo
 ne (Université de Genève\, Suisse)\n\nWe investigate persistent currents
  for a fixed number of fermions in periodic quantum ladders threaded by Ah
 aronov-Bohm and transverse magnetic fluxes Φ and χ. We show that the cou
 pling between ladder legs provides a way to effectively change the ground-
 state fermion-number parity\, by varying χ. We demonstrate that varying 
 χ by 2π (one flux quantum) leads to an apparent fermion-number parity sw
 itch. We find that persistent currents exhibit a robust 4π periodicity as
  a function of χ\, despite the fact that χ→χ+2π leads to modificatio
 ns of order 1/N of the energy spectrum\, where N is the number of sites in
  each ladder leg. We connect the parity switching effect to the quantum Ha
 ll regime in two-dimensional systems. We show that the parity switching ef
 fect is related to the parity of the number of filled Landau levels and th
 at it inherits strong robustness against disorder in the Harper-Hofstadter
  quantum Hall regime. Indeed\, we show that the 4π periodicity is a mesos
 copic manifestation of a novel type of fermionic pumping in topological sy
 stems\, complementary to Thouless' pump.  Focusing on the low-energy edge
  physics in the general framework of Chern-Simons theory\, we discuss this
  alternative type of pumping in the context of integer and fractional quan
 tum Hall systems. Our construction provides an intuitive setting to unders
 tand known effects and explore new ones. In particular\, we show that addi
 ng superconductivity to the picture allows us to recover the 4π Josephson
  effect of Majorana fermions and its generalizations to parafermions.  Th
 e parity-switching and the 4π periodicity effects are robust with respect
  to temperature and disorder and we outline potential physical realization
 s using Corbino disk geometries in solid state systems\, quantum ladders w
 ith cold atomic gases and\, for bosonic analogs of the effects\, photonic 
 lattices.\n\n\nRef:\n\n	Michele Filippone\, Charles-Edouard Bardyn\, Thier
 ry Giamarchi\, Controlled parity switch of persistent currents in quantum 
 ladders\, preprint cond-mat.mes-hall arXiv:1710.02152\n\n\n\n\n&nbsp\;
LOCATION:LPTMS\, salle 201\, 2ème étage\, Bât 100\, Campus d'Orsay\, 15 
 Rue Georges Clemenceau\, Orsay\, 91405\, France
GEO:48.698185;2.181768
X-APPLE-STRUCTURED-LOCATION;VALUE=URI;X-ADDRESS=15 Rue Georges Clemenceau\,
  Orsay\, 91405\, France;X-APPLE-RADIUS=100;X-TITLE=LPTMS\, salle 201\, 2è
 me étage\, Bât 100\, Campus d'Orsay:geo:48.698185,2.181768
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