scholarly journals Unconventional Superconductivity in YPtBi and Related Topological Semimetals

2016 ◽  
Vol 116 (13) ◽  
Author(s):  
Markus Meinert
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sangmo Cheon ◽  
Ki Hoon Lee ◽  
Suk Bum Chung ◽  
Bohm-Jung Yang

AbstractRecently, unconventional superconductivity having a zero-bias conductance peak is reported in doped topological Dirac semimetal (DSM) with lattice distortion. Motivated by the experiments, we theoretically study the possible symmetry-lowering lattice distortions and their effects on the emergence of unconventional superconductivity in doped topological DSM. We find four types of symmetry-lowering lattice distortions that reproduce the crystal symmetries relevant to experiments from the group-theoretical analysis. Considering inter-orbital and intra-orbital electron density-density interactions, we calculate superconducting phase diagrams. We find that the lattice distortions can induce unconventional superconductivity hosting gapless surface Andreev bound states (SABS). Depending on the lattice distortions and superconducting pairing interactions, the unconventional inversion-odd-parity superconductivity can be either topological nodal superconductivity hosting a flat SABS or topological crystalline superconductivity hosting a gapless SABS. Remarkably, the lattice distortions increase the superconducting critical temperature, which is consistent with the experiments. Our work opens a pathway to explore and control pressure-induced topological superconductivity in doped topological semimetals.


2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Zhuoliang Ni ◽  
B. Xu ◽  
M.-Á. Sánchez-Martínez ◽  
Y. Zhang ◽  
K. Manna ◽  
...  

AbstractChiral topological semimetals are materials that break both inversion and mirror symmetries. They host interesting phenomena such as the quantized circular photogalvanic effect (CPGE) and the chiral magnetic effect. In this work, we report a comprehensive theoretical and experimental analysis of the linear and nonlinear optical responses of the chiral topological semimetal RhSi, which is known to host multifold fermions. We show that the characteristic features of the optical conductivity, which display two distinct quasi-linear regimes above and below 0.4 eV, can be linked to excitations of different kinds of multifold fermions. The characteristic features of the CPGE, which displays a sign change at 0.4 eV and a large non-quantized response peak of around 160 μA/V2 at 0.7 eV, are explained by assuming that the chemical potential crosses a flat hole band at the Brillouin zone center. Our theory predicts that, in order to observe a quantized CPGE in RhSi, it is necessary to increase the chemical potential as well as the quasiparticle lifetime. More broadly, our methodology, especially the development of the broadband terahertz emission spectroscopy, could be widely applied to study photogalvanic effects in noncentrosymmetric materials and in topological insulators in a contact-less way and accelerate the technological development of efficient infrared detectors based on topological semimetals.


Nanoscale ◽  
2021 ◽  
Author(s):  
Liangbing Ge ◽  
Ni Kun ◽  
Xiaojun Wu ◽  
Zhengping Fu ◽  
Yalin Lu ◽  
...  

Recent experiments on magic-angle twisted bi-layer graphene have attracted an intensive attention due to exotic properties such as unconventional superconductivity and correlated insulation. These phenomena were often found at a...


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Libo Zhang ◽  
Zhiqingzi Chen ◽  
Kaixuan Zhang ◽  
Lin Wang ◽  
Huang Xu ◽  
...  

AbstractThe advent of topological semimetals enables the exploitation of symmetry-protected topological phenomena and quantized transport. Here, we present homogeneous rectifiers, converting high-frequency electromagnetic energy into direct current, based on low-energy Dirac fermions of topological semimetal-NiTe2, with state-of-the-art efficiency already in the first implementation. Explicitly, these devices display room-temperature photosensitivity as high as 251 mA W−1 at 0.3 THz in an unbiased mode, with a photocurrent anisotropy ratio of 22, originating from the interplay between the spin-polarized surface and bulk states. Device performances in terms of broadband operation, high dynamic range, as well as their high sensitivity, validate the immense potential and unique advantages associated to the control of nonequilibrium gapless topological states via built-in electric field, electromagnetic polarization and symmetry breaking in topological semimetals. These findings pave the way for the exploitation of topological phase of matter for high-frequency operations in polarization-sensitive sensing, communications and imaging.


2017 ◽  
Vol 95 (7) ◽  
Author(s):  
Bohm-Jung Yang ◽  
Troels Arnfred Bojesen ◽  
Takahiro Morimoto ◽  
Akira Furusaki

2001 ◽  
Vol 86 (25) ◽  
pp. 5775-5778 ◽  
Author(s):  
H. Tou ◽  
Y. Maniwa ◽  
T. Koiwasaki ◽  
S. Yamanaka

2007 ◽  
Vol 68 (11) ◽  
pp. 2119-2123 ◽  
Author(s):  
Y. Ihara ◽  
H. Takeya ◽  
K. Ishida ◽  
C. Michioka ◽  
K. Yoshimura ◽  
...  

2021 ◽  
Vol 1 ◽  

We theoretically show that the nodal structures in topological semimetals, including Weyl points and nodal lines, can be switched by magnetic orders, accompanied by localized states at magnetic domain walls.


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