Vortex entropy and superconducting fluctuations in ultrathin underdoped Bi2Sr2CaCu2O8+x superconductor

Hu，Shuxu1; Qiao，Jiabin1,2,3; Gu，Genda4; Xue，Qi Kun1,3,5,6; Zhang，Ding1,3,6,7

2024-12-01

10.1038/s41467-024-48899-6

Nature Communications   影响因子和分区

2041-1723

Vortices in superconductors can help identify emergent phenomena but certain fundamental aspects of vortices, such as their entropy, remain poorly understood. Here, we study the vortex entropy in underdoped BiSrCaCuO by measuring both magneto-resistivity and Nernst effect on ultrathin flakes (≤2 unit-cell). We extract the London penetration depth from the magneto-transport measurements on samples with different doping levels. It reveals that the superfluid phase stiffness ρ scales linearly with the superconducting transition temperature T, down to the extremely underdoped case. On the same batch of ultrathin flakes, we measure the Nernst effect via on-chip thermometry. Together, we obtain the vortex entropy and find that it decays exponentially with T or ρ. We further analyze the Nernst signal above T in the framework of Gaussian superconducting fluctuations. The combination of electrical and thermoelectric measurements in the two-dimensional limit provides fresh insight into high temperature superconductivity.

英语

NI期刊

其他

2-s2.0-85195439031

Scopus

1.State Key Laboratory of Low Dimensional Quantum Physics and Department of Physics,Tsinghua University,Beijing,China
2.Centre for Quantum Physics,Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement,School of Physics,Beijing Institute of Technology,Beijing,China
3.Beijing Academy of Quantum Information Sciences,Beijing,China
4.Condensed Matter Physics and Materials Science Department,Brookhaven National Laboratory,Upton,United States
5.Southern University of Science and Technology,Shenzhen,China
6.Frontier Science Center for Quantum Information,Beijing,China
7.RIKEN Center for Emergent Matter Science (CEMS),Wako,Saitama,Japan

Hu，Shuxu,Qiao，Jiabin,Gu，Genda,et al. Vortex entropy and superconducting fluctuations in ultrathin underdoped Bi2Sr2CaCu2O8+x superconductor[J]. Nature Communications,2024,15(1).

Hu，Shuxu,Qiao，Jiabin,Gu，Genda,Xue，Qi Kun,&Zhang，Ding.(2024).Vortex entropy and superconducting fluctuations in ultrathin underdoped Bi2Sr2CaCu2O8+x superconductor.Nature Communications,15(1).

Hu，Shuxu,et al."Vortex entropy and superconducting fluctuations in ultrathin underdoped Bi2Sr2CaCu2O8+x superconductor".Nature Communications 15.1(2024).