Nanocalorimetric evidence for nematic superconductivity in the doped topological insulator Sr0.1Bi2Se3

被引：34

作者：

Willa, Kristin ^{[1
]}

Willa, Roland ^{[1
]}

Song, Kok Wee ^{[1
]}

Gu, G. D. ^{[2
]}

Schneeloch, John A. ^{[2
,3
]}

Zhong, Ruidan ^{[2
,4
]}

Koshelev, Alexei E. ^{[1
]}

Kwok, Wai-Kwong ^{[1
]}

Welp, Ulrich ^{[1
]}

机构：

[1] Argonne Natl Lab, Mat Sci Div, Lemont, IL 60439 USA

[2] Brookhaven Natl Lab, Condensed Matter Phys & Mat Sci Dept, Upton, NY 11793 USA

[3] SUNY Stony Brook, Dept Phys & Astron, Stony Brook, NY 11794 USA

[4] SUNY Stony Brook, Dept Mat Sci & Engn, Stony Brook, NY 11794 USA

来源：

PHYSICAL REVIEW B | 2018年 / 98卷 / 18期

基金：

瑞士国家科学基金会;

关键词：

PHASE-DIAGRAM; UPT3;

D O I：

10.1103/PhysRevB.98.184509

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

Spontaneous rotational-symmetry breaking in the superconducting state of doped Bi2Se3 has attracted significant attention as an indicator for topological superconductivity. In this paper, high-resolution calorimetry of the single-crystal Sr0.1Bi2Se3 provides unequivocal evidence of a twofold rotational symmetry in the superconducting gap by a bulk thermodynamic probe, a fingerprint of nematic superconductivity. The extremely small specific heat anomaly resolved with our high-sensitivity technique is consistent with the material's low carrier concentration proving bulk superconductivity. The large basal-plane anisotropy of H-c(2) (Gamma(exp) = 3.5) is attributed to a nematic phase of a two-component topological gap structure eta = (eta(1), eta(2)) and caused by a symmetry-breaking energy term delta (vertical bar eta(1)vertical bar(2) - vertical bar eta(2)vertical bar(2))T-c. A quantitative analysis of our data excludes more conventional sources of this twofold anisotropy and provides an estimate for the symmetry-breaking strength delta approximate to 0.1, a value that points to an onset transition of the second order parameter component below 2 K.

引用

页数：6

共 42 条

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