BEGIN:VCALENDAR
VERSION:2.0
PRODID:icalendar-ruby
CALSCALE:GREGORIAN
METHOD:PUBLISH
BEGIN:VTIMEZONE
TZID:Europe/Vienna
BEGIN:DAYLIGHT
DTSTART:20240331T030000
TZOFFSETFROM:+0100
TZOFFSETTO:+0200
RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=3
TZNAME:CEST
END:DAYLIGHT
BEGIN:STANDARD
DTSTART:20231029T020000
TZOFFSETFROM:+0200
TZOFFSETTO:+0100
RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=10
TZNAME:CET
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
DTSTAMP:20260424T143347Z
UID:1706097600@ist.ac.at
DTSTART:20240124T130000
DTEND:20240124T140000
DESCRIPTION:Speaker: Anton Khvalyuk\nhosted by Maksym Serbyn\nAbstract: Sup
 erconductors are characterized by appearance of a finite current density j
  = − 1/c \\rho_S A in response to a locally homogeneous time-independent
  external vector potential A\, with \\rho_S being the superfluid density.
  In relatively clean BCS superconductors\, \\rho_S only weakly depends on
  temperature due an exponentially low density of thermal quasiparticles. H
 owever\, strong nonmagnetic disorder is known to drastically modify the si
 tuation. Noteably\, the normal state eventually becomes insulating with a 
 hard gap in the single-particle density of states — a so-called pseudoga
 p. In this talk\, we report direct measurement of \\rho_S(T) in a strongly
  disordered pseudo-gaped superconductor\, amorphous InO_x\, revealing an u
 nusually strong power-law suppression of the superfluid stiffness \\delta 
 \\rho_S(T) \\propto T^b at T much less than T_c\, with b ∼ 1.6. We then 
 address this issue theoretically within a certain model of a disordered su
 perconductor with a pseudogap\, resulting in a similar low-temperature pow
 er-law behavior with exponent b ∼ 1.6 − 3 being disorder-dependent. Th
 is power-law suppression of the superfluid density occurs mainly due to th
 e broad distribution of the superconducting order parameter that is known 
 to exist in such superconductors [arXiv:1012.3630]. Our observations demon
 starte the existence of low-energy excitations and imply a new channel of 
 dissipation associated to the latter\, while the pseudogap rules out the q
 uaisparticles. Our findings have implications for the use of strongly diso
 rdered superconductors as superinductance in quantum circuits. The talk is
  based on our recent paper [arXiv:2311.15126].
LOCATION:Central Bldg / O1 / Mondi 2a + b \, ISTA
ORGANIZER:dafne.valdez@ist.ac.at
SUMMARY:Anton Khvalyuk: Low-temperature dependence of the superfluid densit
 y in strongly disordered superconductors.
URL:https://talks-calendar.ista.ac.at/events/4754
END:VEVENT
END:VCALENDAR