scholarly journals Effect of Rashba Impurities on Surface State of a Topological Kondo Insulator

Surfaces ◽  
2020 ◽  
Vol 3 (3) ◽  
pp. 484-504
Author(s):  
Partha Goswami
Keyword(s):  
Critical Point ◽  
Wave Vector ◽  
Surface State ◽  
Quantum Critical Point ◽  
Mean Field ◽  
Electron Localization ◽  
Present Communication ◽  
Kondo Insulator ◽  
Dirac Spectrum ◽  
Rashba Coupling

In this communication, we report surface state, with Rashba impurities, of a generic topological Kondo insulator (TKI) system by performing a mean-field theoretic (MFT) calculation within the framework of slave-boson protocol. The surface metallicity together with bulk insulation is found to require very strong f-electron localization. The possibility of intra-band as well as inter-band unconventional plasmons exists for the surface state spectrum. The paramountcy of the bulk metallicity, and, in the presence of the Rashba impurities, the TKI surface comprising of ‘helical liquids’ are the important outcomes of the present communication. The access to the gapless Dirac spectrum leads to spin-plasmons with the usual wave vector dependence q1/2. The Rashba coupling does not impair the Kondo screening and does not affect the quantum critical point (QCP) for the bulk.

scholarly journals On Strong f-Electron Localization Effect in a Topological Kondo Insulator

Symmetry ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2245
Author(s):  
Udai Prakash Tyagi ◽  
Kakoli Bera ◽  
Partha Goswami
Keyword(s):  
Topological Insulator ◽  
Surface State ◽  
Mean Field ◽  
Surface States ◽  
Pictorial Representation ◽  
Electron Localization ◽  
Surface Band ◽  
Kondo Insulator ◽  
Localization Effect ◽  
Generic System

We study a strong f-electron localization effect on the surface state of a generic topological Kondo insulator (TKI) system by performing a mean-field theoretic (MFT) calculation within the framework of the periodic Anderson model (PAM) using the slave boson technique. The surface metallicity, together with bulk insulation, requires this type of localization. A key distinction between surface states in a conventional insulator and a topological insulator is that, along a course joining two time-reversal invariant momenta (TRIM) in the same BZ, there will be an intersection of these surface states, an even/odd number of times, with the Fermi energy inside the spectral gap. For an even (odd) number of surface state crossings, the surface states are topologically trivial (non-trivial). The symmetry consideration and the pictorial representation of the surface band structure obtained here show an odd number of crossings, leading to the conclusion that, at least within the PAM framework, the generic system is a strong topological insulator.

scholarly journals Tuning the charge density wave quantum critical point and the appearance of superconductivity in TiSe2

2021 ◽  
Vol 3 (3) ◽  
Author(s):  
Sangyun Lee ◽  
Tae Beom Park ◽  
Jihyun Kim ◽  
Soon-Gil Jung ◽  
Won Kyung Seong ◽  
...  
Keyword(s):  
Charge Density ◽  
Critical Point ◽  
Charge Density Wave ◽  
Density Wave ◽  
Quantum Critical Point ◽  
Quantum Critical

scholarly journals Lattice-shifted nematic quantum critical point in FeSe1−xSx

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
S. Chibani ◽  
D. Farina ◽  
P. Massat ◽  
M. Cazayous ◽  
A. Sacuto ◽  
...  
Keyword(s):  
Transition Temperature ◽  
Critical Point ◽  
Degrees Of Freedom ◽  
Quantum Critical Point ◽  
Substantial Effect ◽  
Low Energy ◽  
Elastic Coupling ◽  
Superconducting Transition ◽  
Local Moments ◽  
Quantum Critical

AbstractWe report the evolution of nematic fluctuations in FeSe1−xSx single crystals as a function of Sulfur content x across the nematic quantum critical point (QCP) xc ~ 0.17 via Raman scattering. The Raman spectra in the B1g nematic channel consist of two components, but only the low energy one displays clear fingerprints of critical behavior and is attributed to itinerant carriers. Curie–Weiss analysis of the associated nematic susceptibility indicates a substantial effect of nemato-elastic coupling, which shifts the location of the nematic QCP. We argue that this lattice-induced shift likely explains the absence of any enhancement of the superconducting transition temperature at the QCP. The presence of two components in the nematic fluctuations spectrum is attributed to the dual aspect of electronic degrees of freedom in Hund’s metals, with both itinerant carriers and local moments contributing to the nematic susceptibility.

scholarly journals Avoided ferromagnetic quantum critical point in pressurized La5Co2Ge3

2021 ◽  
Vol 103 (5) ◽  
Author(s):  
Li Xiang ◽  
Elena Gati ◽  
Sergey L. Bud'ko ◽  
Scott M. Saunders ◽  
Paul C. Canfield
Keyword(s):  
Critical Point ◽  
Quantum Critical Point ◽  
Quantum Critical

scholarly journals Multiband nodeless superconductivity near the charge-density-wave quantum critical point in ZrTe 3− x Se x

2016 ◽  
Vol 25 (7) ◽  
pp. 077403
Author(s):  
Shan Cui ◽  
Lan-Po He ◽  
Xiao-Chen Hong ◽  
Xiang-De Zhu ◽  
Cedomir Petrovic ◽  
...  
Keyword(s):  
Charge Density ◽  
Critical Point ◽  
Charge Density Wave ◽  
Density Wave ◽  
Quantum Critical Point ◽  
Quantum Critical
Sign in / Sign up

Export Citation Format

Share Document