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SR studies of the pressure dependent superconducting Formatvorlage des Untertitelmasters durch Klicken bearbeiten properties of Ca 3 Ir 4 Sn 13 Manuel Chinotti | | 17.01.16 1 Phase diagram of Ca 3 Ir 4 Sn 13 Anomaly around 33 K

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Formatvorlage des Untertitelmasters durch Klicken bearbeiten 17.01.16 1

μSR studies of the pressure dependent superconducting properties of Ca3Ir4Sn13

Manuel Chinotti

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Manuel Chinotti 2

Phase diagram of Ca3Ir4Sn13

Close to pc (around 18 kbar) find behavior of:

Superfluid density
Superconducting gap
Symmetry of the gap

CDW SC CDW+SC

L.E. Klintberg et al., PRL 109, 237008 (2012)

Anomaly around 33 K
Critical temperature around 7 K

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Manuel Chinotti 3

μSR of Ca3Ir4Sn13 under pressure

Measurements in:

TF-field: 500 G.
Temperature range 0.25 K -10 K.
Pressure range: 1.5 kbar-21.8 kbar

Find average internal field, muon depolarization rate and penetration depth.

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Manuel Chinotti 4

μSR: local probe technique

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Manuel Chinotti 5

μSR of Ca3Ir4Sn13 under pressure

Cu-Be p-cell MP35N p-cell SC non SC

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Manuel Chinotti 6

μSR of Ca3Ir4Sn13 under pressure

Cu-Be-cell MP35N-cell

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Manuel Chinotti 7

μSR of Ca3Ir4Sn13 under pressure

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Manuel Chinotti 8

μSR of Ca3Ir4Sn13 under pressure

Dirty superconductor: mean free path << BCS coherence length
Nodeless superconductor at each pressure
Behavior of Tc and of superfluid density different from BCS superconductors

s-wave model in dirty limit

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Manuel Chinotti 9

μSR of Ca3Ir4Sn13 under pressure

Type II SC
QCP: 15-16 kbar
CDW gap suppressed

L.E. Klintberg et al., PRL 109, 237008 (2012)

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Manuel Chinotti 10

μSR of Ca3Ir4Sn13 under pressure

Strong-coupling SC

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Manuel Chinotti 11

Summary

Dirty, strong-coupling, type-II superconductor.
Nodeless single gap BCS s-wave model.
Superfluid density of Ca3Ir4Sn13 increases dramatically under

pressure.

This is possibly due to suppression of CDW gap under pressure at

about 15 kbar.

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Manuel Chinotti 12

Literature

P.K. Biswas et al.,Phys. Rev. B 92, 195122 (2015).
P.K. Biswas et al.,Phys. Rev. B 90, 144505 (2014).
S.J. Blundell, Contemporary Physics 40, 203-225 (2004)