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SUMMARY:Can the Fermi surface reconstruction in YBCO at high fields be exp
 lained  by the observed Charge Density Wave (CDW) structure? - Ted Forgan\
 , University of Birmingham
DTSTART:20150917T131500Z
DTEND:20150917T141500Z
UID:TALK60742@talks.cam.ac.uk
CONTACT:Gareth Conduit
DESCRIPTION:Recent pulsed-X-ray\, pulsed-magnetic-field measurements (Gerb
 er et al. arXiv :1506.07910) have revealed a new high-field CDW structure 
 in underdoped YBCO. We have extended these measurements in static (but not
  so high) fields to give a more detailed picture of the high-field structu
 re and field-temperature-doping phase diagram\, as well as how they evolve
  out of the low field structure (Chang et al.\, in preparation). Compariso
 n with our CDW structure determination at zero field (Forgan et al. arXiv:
 1504.01585) allows us to determine the symmetry of the CDW in the high-fie
 ld phase. With this new information\, we can include CDW and spin-orbit (S
 -O) interactions in a tight-binding representation of the electronic struc
 ture in the CuO2 planes to calculate the expected reconstruction of the Fe
 rmi surface sheets (Briffa et al.\, in preparation). These calculations re
 veal that magnetic breakdown across small gaps and spin-flips due to S-O a
 re important features (see also Harrison et al. Sci. Rep. 5\, 10914 (2015)
 ). It appears that our minimal Fermi liquid approach can account for the q
 uantum oscillation and other experimental data in the underdoped state of 
 this benchmark cuprate\, although some fascinating questions remain.
LOCATION:TCM Seminar Room\, Cavendish Laboratory
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