BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//talks.bham.ac.uk//v3//EN
BEGIN:VEVENT
CATEGORIES:Theoretical Physics Seminars
SUMMARY:Anomalous thermodynamic exponents from topological
transitions in nodal superconductors - Dr. Jorge
Quintanilla\, University of Kent
DTSTART:20131114T134500Z
DTEND:20131114T150000Z
UID:TALK1083AT
URL:/talk/index/1083
DESCRIPTION:\n\nI will describe a simple generalisation of the
theory of nodal quasiparticles and use it to deri
ve a bulk thermodynamic signature of certain topol
ogical transitions.\nThe theory of nodal quasipart
icles has a wide range of applications\, from unco
nventional superconductors to topological supercon
ductors and graphene. At low temperatures\, their
linear dispersion away from a nodal point or line
on the Fermi surface (a Dirac point or a Dirac lin
e)\, leads to a characteristic power-law dependenc
e of the specific heat:\n\n\n\nIn superconductors\
, such behaviour can be used to detect experimenta
lly whether the order parameter has line nodes (n
= 2) or point nodes (n = 3) and therefore to ident
ify the Cooper pairing symmetry. I this talk I wil
l show that other\, non-integer exponents are poss
ible. These occur when line nodes cross or near to
pological transitions where point nodes\, line nod
es\, or line node crossings either appear\, disapp
ear or re-configure themselves in a non-trival way
on the Fermi surface (e.g.\, at a line reconnecti
on transition where the number of rings of line no
des on the Fermi surface changes). Such anomalous
exponents thus provide bulk thermodynamic signatur
es of the topological transitions in question.\n\n
Interestingly\, you don’t need to be exactly at th
e transition in order to observe the anomalous exp
onent – merely being near the transition is enough
to observe the anomalous power law down to some c
haracteristic temperature scale T* below which the
more conventional behaviour is found – a behaviou
r strongly reminiscent of a quantum critical endpo
int (QCEP).\n\n[1] B. Mazidian\, J. Quintanilla\,
A.D. Hillier\, J.F. Annett\, arXiv:1302.2161
LOCATION:Theory Library
CONTACT:Kevin Ralley
END:VEVENT
END:VCALENDAR