scholarly journals Surface spectral function in the superconducting state of a topological insulator

2011 ◽  
Vol 83 (13) ◽  
Author(s):  
Lei Hao ◽  
T. K. Lee
Keyword(s):  
Spectral Function ◽  
Topological Insulator ◽  
Superconducting State

scholarly journals SPECTRAL ANOMALY AND HIGH TEMPERATURE SUPERCONDUCTORS

1996 ◽  
Vol 10 (07) ◽  
pp. 805-845 ◽  
Author(s):  
LAN YIN ◽  
SUDIP CHAKRAVARTY
Keyword(s):  
High Temperature ◽  
Spectral Function ◽  
Superconducting State ◽  
Fermi Liquid ◽  
Cuprate Superconductors ◽  
High Temperature Superconductors ◽  
Universality Class ◽  
Scaling Relation ◽  
Critical System ◽  
Spectral Anomaly

Spectral anomaly for interacting fermions is characterized by the spectral function A ([k − k F ], ω) satisfying the scaling relation A (Λy1 [k − k F ], Λy2 ω) =ΛyA A ([k − k F ], ω), where y1, y2, and yA are the exponents defining the universality class. For a Fermi liquid y1 = 1, y2 = 1, yA = −1; all other values of the exponents are termed anomalous. In this paper, an example for which y1 = 1, y2 = 1, but yA = α − 1 is considered in detail. Attractive interaction added to such a critical system leads to a novel superconducting state, which is explored and its relevance to high temperature cuprate superconductors is discussed.

scholarly journals Investigations of proximity-induced superconductivity in the topological insulator Bi2Te3 by microRaman spectroscopy

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
D. Kiphart ◽  
Y. Harkavyi ◽  
K. Balin ◽  
J. Szade ◽  
B. Mróz ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Charge Transport ◽  
Topological Insulator ◽  
Superconducting State ◽  
High Temperature Superconductor ◽  
Superconducting Gap ◽  
Pseudogap State ◽  
Hybrid Device ◽  
Higher Temperature ◽  
Microraman Spectroscopy

AbstractWe used the topological insulator (TI) Bi2Te3 and a high-temperature superconductor (HTSC) hybrid device for investigations of proximity-induced superconductivity (PS) in the TI. Application of the superconductor YBa2Cu3O7-δ (YBCO) enabled us to access higher temperature and energy scales for this phenomenon. The HTSC in the hybrid device exhibits emergence of a pseudogap state for T > Tc that converts into a superconducting state with a reduced gap for T < Tc. The conversion process has been reflected in Raman spectra collected from the TI. Complementary charge transport experiments revealed emergence of the proximity-induced superconducting gap in the TI and the reduced superconducting gap in the HTSC, but no signature of the pseudogap. This allowed us to conclude that Raman spectroscopy reveals formation of the pseudogap state but cannot distinguish the proximity-induced superconducting state in the TI from the superconducting state in the HTSC characterised by the reduced gap. Results of our experiments have shown that Raman spectroscopy is a complementary technique to classic charge transport experiments and is a powerful tool for investigation of the proximity-induced superconductivity in the Bi2Te3.

Pressure induced superconducting state in ideal topological insulator BiSbTe3

2021 ◽  
Vol 96 (5) ◽  
pp. 055802
Author(s):  
Vinod K Gangwar ◽  
Shiv Kumar ◽  
Mahima Singh ◽  
Labanya Ghosh ◽  
Yufeng Zhang ◽  
...  
Keyword(s):  
Topological Insulator ◽  
Superconducting State

Observation by HVEM of the martensite transformation and the superconducting transition in Nb3Sn

1988 ◽  
Vol 46 ◽  
pp. 788-789
Author(s):  
M. A. Kirk ◽  
M. C. Baker ◽  
B. J. Kestel ◽  
H. W. Weber
Keyword(s):  
Thin Films ◽  
Low Temperature ◽  
Superconducting State ◽  
Martensite Transformation ◽  
Sputter Deposition ◽  
Diffusion Reaction ◽  
Solute Diffusion ◽  
Superconducting Transition ◽  
Twin Boundaries ◽  
Martensite Structure

It is well known that a number of compound superconductors with the A15 structure undergo a martensite transformation when cooled to the superconducting state. Nb3Sn is one of those compounds that transforms, at least partially, from a cubic to tetragonal structure near 43 K. To our knowledge this transformation in Nb3Sn has not been studied by TEM. In fact, the only low temperature TEM study of an A15 material, V3Si, was performed by Goringe and Valdre over 20 years ago. They found the martensite structure in some foil areas at temperatures between 11 and 29 K, accompanied by faults that consisted of coherent twin boundaries on {110} planes. In pursuing our studies of irradiation defects in superconductors, we are the first to observe by TEM a similar martensite structure in Nb3Sn.Samples of Nb3Sn suitable for TEM studies have been produced by both a liquid solute diffusion reaction and by sputter deposition of thin films.

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