BEGIN:VCALENDAR
VERSION:2.0
CALSCALE:GREGORIAN
PRODID:UW-Madison-Physics-Events
BEGIN:VEVENT
SEQUENCE:0
UID:UW-Physics-Event-2809
DTSTART:20121001T163000Z
DURATION:PT1H0M0S
DTSTAMP:20260420T034658Z
LAST-MODIFIED:20120925T131049Z
LOCATION:5310 Chamberlin
SUMMARY:Tunneling spectroscopy of many-body effects in a two-dimension
 al electron gas of near-surface delta-doped layer\, Special Seminar\, 
 Sergey Dizhur\, Institute of Radioengineering & Electronics\, Russian 
 Academy of Science
DESCRIPTION:The Al/delta-GaAs tunnel junctions with different subbands
  spectra in the 2D electron system (2DES) of delta-layer were studied.
  In each of the junctions subband energies Ei in 2DES can be changed b
 y the diamagnetic shift or by the persistent tunnelling photoconductiv
 ity (PTPC) effect. The change of tunnelling conductance at the LO-phon
 on emission threshold was investigated. The negative change of conduct
 ance (electron reflection) was observed for tunnelling in two subband 
 (empty E1 and occupied E0)\, when intersubband LO-phonon emission into
  2DES was possible. The crossover of the zero point in conductance cha
 nge was found when the energy difference E1F between E1 and the Fermi 
 level EF in 2DES becomes more then LO-phonon energy. In the case the u
 sual inelastic LO-phonon-assisted processes dominate and the new (inel
 astic) channel is added to the elastic one (positive change).<br>
\n<b
 r>
\nThe obtained results show that the reflection of electrons is rel
 ated to a new subband being involved in the tunneling process and to t
 he emission of LO-phonons under electron transitions from this subband
  to the ground state in the 2DES region.
URL:https://www.physics.wisc.edu/events/?id=2809
END:VEVENT
END:VCALENDAR