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VERSION:2.0
CALSCALE:GREGORIAN
PRODID:UW-Madison-Physics-Events
BEGIN:VEVENT
SEQUENCE:1
UID:UW-Physics-Event-8871
DTSTART:20241212T160000Z
DTEND:20241213T000000Z
DTSTAMP:20260413T171619Z
LAST-MODIFIED:20241210T150614Z
LOCATION:5310 Chamberlin
SUMMARY:Topology and phase transitions in twisted nodal superconductor
 s and beyond\, R. G. Herb Condensed Matter Seminar\, Pavel Volkov\, Un
 iversity of Connecticut
DESCRIPTION:“Twistronics” paradigm has been tremendously successfu
 l in realizing strongly correlated and topological phases of electrons
  in two-dimensional semiconductors or semimetals. In my talk\, I will 
 show that twisted bilayers of nodal superconductors allow a similar de
 gree of control over the neutral quasiparticles in superconductors.
\n
 I will demonstrate that the spectrum of the superconducting Dirac quas
 iparticles close to the gap nodes is strongly renormalized by twisting
  and can be further controlled externally. In particular\, the applica
 tion of an interlayer current transforms the system into a topological
  superconductor at any nonzero twist angle\, while magnetic field can 
 be used to create periodic lattices of alternating Chern domains [1]. 
 Moreover\, at large twist angles near 45°\, frustrated Josephson coup
 ling can drive spontaneous time-reversal breaking. A promising platfor
 m to observe these effects is provided by the high-Tc cuprates\, and I
  will discuss the theoretical description of the experimental results 
 on twisted flakes of Bi2Sr2CaCu2O8+x [2].
\nMoving on from superconduc
 tors\, I will discuss the ongoing work on elucidating more broadly the
  role of symmetries in moire materials\, with the example of realizati
 on of t-t’-U Hubbard models in twisted square lattice materials [3].
 
\n[1] P. A. Volkov\, K. P. Lucht\, J. H. Wilson and J. H. Pixley\, Ph
 ysical Review Letters 130\, 186001 (2023)
\n[2] S. Y. F. Zhao\, X. Cui
 \, P. A. Volkov\, …\, P. Kim\, Science 382\, 6677\, 1422 (2023).
\n[
 3] P. M. Eugenio\, Z-X Luo\, A. Vishwanath\, P. A. Volkov\, arXiv:2406
 .02448
\n
\nYou can also get more information on Pavel's website pavol
 kov.com
\n
URL:https://www.physics.wisc.edu/events/?id=8871
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