Unconventional superconductivity in Y5 Rh6 Sn18 probed by muon spin relaxation

Amitava Bhattacharyya, Devashibhai Adroja, Naoki Kase, Adrian Hillier, Jun Akimitsu, Andre Strydom

Research output: Contribution to journalArticle

11 Citations (Scopus)

Abstract

Conventional superconductors are robust diamagnets that expel magnetic fields through the Meissner effect. It would therefore be unexpected if a superconducting ground state would support spontaneous magnetics fields. Such broken time-reversal symmetry states have been suggested for the high-temperature superconductors, but their identification remains experimentally controversial. We present magnetization, heat capacity, zero field and transverse field muon spin relaxation experiments on the recently discovered caged type superconductor Y5Rh6Sn18 ( TC= 3.0 K). The electronic heat capacity of Y5Rh6Sn18 shows a T3 dependence below Tc indicating an anisotropic superconducting gap with a point node. This result is in sharp contrast to that observed in the isostructural Lu5Rh6Sn18 which is a strong coupling s-wave superconductor. The temperature dependence of the deduced superfluid in density Y5Rh6Sn18 is consistent with a BCS s-wave gap function, while the zero-field muon spin relaxation measurements strongly evidences unconventional superconductivity through a spontaneous appearance of an internal magnetic field below the superconducting transition temperature, signifying that the superconducting state is categorized by the broken time-reversal symmetry.

Original languageEnglish
Article number12926
JournalScientific Reports
Volume5
DOIs
Publication statusPublished - Aug 19 2015
Externally publishedYes

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muons
superconductivity
magnetic fields
specific heat
Meissner effect
symmetry
high temperature superconductors
transition temperature
magnetization
temperature dependence
ground state
electronics

ASJC Scopus subject areas

  • General

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Unconventional superconductivity in Y5 Rh6 Sn18 probed by muon spin relaxation. / Bhattacharyya, Amitava; Adroja, Devashibhai; Kase, Naoki; Hillier, Adrian; Akimitsu, Jun; Strydom, Andre.

In: Scientific Reports, Vol. 5, 12926, 19.08.2015.

Research output: Contribution to journalArticle

Bhattacharyya, Amitava ; Adroja, Devashibhai ; Kase, Naoki ; Hillier, Adrian ; Akimitsu, Jun ; Strydom, Andre. / Unconventional superconductivity in Y5 Rh6 Sn18 probed by muon spin relaxation. In: Scientific Reports. 2015 ; Vol. 5.
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