scholarly journals Quantum phases of disordered three-dimensional Majorana-Weyl fermions

2017 ◽  
Vol 95 (15) ◽  
Author(s):  
Justin H. Wilson ◽  
J. H. Pixley ◽  
Pallab Goswami ◽  
S. Das Sarma
Keyword(s):  
Three Dimensional ◽  
Quantum Phases ◽  
Weyl Fermions

scholarly journals Symmetry-enriched quantum spin liquids in (3 + 1)d

2020 ◽  
Vol 2020 (9) ◽  
Author(s):  
Po-Shen Hsin ◽  
Alex Turzillo
Keyword(s):  
Gauge Theory ◽  
Gauge Field ◽  
Quantum Spin ◽  
Global Symmetry ◽  
Spin Liquids ◽  
Systematic Method ◽  
Bosonic Field ◽  
Quantum Phases ◽  
Symmetry Protected ◽  
Weyl Fermions

Abstract We use the intrinsic one-form and two-form global symmetries of (3+1)d bosonic field theories to classify quantum phases enriched by ordinary (0-form) global symmetry. Different symmetry-enriched phases correspond to different ways of coupling the theory to the background gauge field of the ordinary symmetry. The input of the classification is the higher-form symmetries and a permutation action of the 0-form symmetry on the lines and surfaces of the theory. From these data we classify the couplings to the background gauge field by the 0-form symmetry defects constructed from the higher-form symmetry defects. For trivial two-form symmetry the classification coincides with the classification for symmetry fractionalizations in (2 + 1)d. We also provide a systematic method to obtain the symmetry protected topological phases that can be absorbed by the coupling, and we give the relative ’t Hooft anomaly for different couplings. We discuss several examples including the gapless pure U(1) gauge theory and the gapped Abelian finite group gauge theory. As an application, we discover a tension with a conjectured duality in (3 + 1)d for SU(2) gauge theory with two adjoint Weyl fermions.

scholarly journals Tunable Berry curvature and transport crossover in topological Dirac semimetal KZnBi

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Junseong Song ◽  
Byung Cheol Park ◽  
Kyung Ik Sim ◽  
Joonho Bang ◽  
Sunghun Kim ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Hall Resistance ◽  
Rotational Axis ◽  
Material System ◽  
Chiral Fermion ◽  
Quantum Phases ◽  
Berry Curvature ◽  
Dirac Semimetal ◽  
Dirac Semimetals ◽  
Single Material

AbstractTopological Dirac semimetals have emerged as a platform to engineer Berry curvature with time-reversal symmetry breaking, which allows to access diverse quantum states in a single material system. It is of interest to realize such diversity in Dirac semimetals that provides insight on correlation between Berry curvature and quantum transport phenomena. Here, we report the transition between anomalous Hall and chiral fermion states in three-dimensional topological Dirac semimetal KZnBi, which is demonstrated by tuning the direction and flux of Berry curvature. Angle-dependent magneto-transport measurements show that both anomalous Hall resistance and positive magnetoresistance are maximized at 0° between net Berry curvature and rotational axis. We find that the unexpected crossover of anomalous Hall resistance and negative magnetoresistance suddenly occurs when the angle reaches to ~70°, indicating that Berry curvature strongly correlates with quantum transports of Dirac and chiral fermions. It would be interesting to tune Berry curvature within other quantum phases such as topological superconductivity.

Three-dimensional borophene: A light-element topological nodal-line semimetal with direction-dependent type-II Weyl fermions

2020 ◽  
Vol 102 (15) ◽  
Author(s):  
Leyuan Cui ◽  
Tielei Song ◽  
Jiangtao Cai ◽  
Xin Cui ◽  
Zhifeng Liu ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Light Element ◽  
Nodal Line ◽  
Type Ii ◽  
Dependent Type ◽  
Weyl Fermions

scholarly journals Quantum Phases of Three-Dimensional Chiral Topological Insulators on a Spin Quantum Simulator

2020 ◽  
Vol 125 (9) ◽  
Author(s):  
Tao Xin ◽  
Yishan Li ◽  
Yu-ang Fan ◽  
Xuanran Zhu ◽  
Yingjie Zhang ◽  
...  
Keyword(s):  
Topological Insulators ◽  
Three Dimensional ◽  
Quantum Phases ◽  
Spin Quantum ◽  
Quantum Simulator

scholarly journals Multicomponent fluctuation spectrum at the quantum critical point in CeCu6−xAgx

2019 ◽  
Vol 4 (1) ◽  
Author(s):  
Lekh Poudel ◽  
Jon M. Lawrence ◽  
Liusuo S. Wu ◽  
Georg Ehlers ◽  
Yiming Qiu ◽  
...  
Keyword(s):  
Quantum Critical Point ◽  
Three Dimensional ◽  
Antiferromagnetic Order ◽  
Fluctuation Spectrum ◽  
Critical Fluctuation ◽  
Single Wave ◽  
Quantum Phases ◽  
Quantum Critical Points ◽  
Long Wavelength ◽  
Quantum Critical

Abstract Quantum critical points (QCPs) are widely accepted as a source of a diverse set of collective quantum phases of matter. The basic nature of a QCP is manifested in the critical fluctuation spectrum which in turn is determined by the adjacent phases and associated order parameters. Here we show that the critical fluctuation spectrum of CeCu5.8Ag0.2 can not be explained by fluctuations associated with a single wave vector. Interestingly, when the critical fluctuations at wave vectors corresponding to the incommensurate antiferromagnetic order adjacent to the QCP are separated they are found to be three dimensional and to obey the scaling behavior expected for long wavelength fluctuations near an itinerant antiferromagnetic QCP. Without this separation, E/T scaling with a fractional exponent is observed. Together these results demonstrate that a multicomponent fluctuation spectrum is a previously unexplored route to obtaining E/T scaling at a QCP.

Collective modes of type-II Weyl fermions with repulsive S-wave interaction

2021 ◽  
Author(s):  
XunGao Wang ◽  
Yuan Sun ◽  
Liang Liu ◽  
WuMing Liu
Keyword(s):  
Fermi Surface ◽  
Random Phase ◽  
Three Dimensional ◽  
Wave Interaction ◽  
Repulsive Interaction ◽  
Type I ◽  
Type Ii ◽  
S Wave ◽  
Momentum Direction ◽  
Weyl Fermions

Abstract Three-dimensional type-II Weyl fermions possess overtilted conelike low-energy band dispersion. Unlike the closed ellipsoidal Fermi surface for type-I Weyl fermions, the Fermi surface is an open hyperboloid for type-II Weyl fermions. We evaluate the spin and density susceptibility of type-II Weyl fermions with repulsive S-wave interaction by means of Green’s functions. We obtain the particle-hole continuum along the tilted momentum direction and perpendicular to the tilted momentum direction, respectively. We find the zero sound mode in some repulsive interaction strengths by numerically solving the pole equations of the susceptibility within the random-phase approximation.

Sign in / Sign up

Export Citation Format

Share Document