Related papers: Quantum oscillation in narrow-gap topological insu…
We performed angle dependent magnetoresistance study of a metallic single crystal sample of Bi2Te3. We find that the magnetoresistance is highly asymmetric in positive and negative magnetic fields for small angles between the magnetic field…
In the search of topological superconductors, nailing down the Fermiology of the normal state is as crucial a prerequisite as unraveling the superconducting pairing symmetry. In particular, the number of time-reversal-invariant momenta in…
Low-temperature quantum oscillations of the dHvA amplitude are shown to persist far below the upper critical field of a strongly type-II superconductor, due to the gapless nature of the BCS quasiparticle spectrum in high fields. The dHvA…
We report magneto-transport studies of InAs/GaSb bilayer quantum wells in a regime where the interlayer tunneling between the electron and hole gases is suppressed. When the chemical potential is tuned close to the charge neutrality point,…
Thermoelectric coefficients of an ultra-thin topological insulator are presented here. The hybridization between top and bottom surface states of a topological insulator plays a significant role. In absence of magnetic field, thermopower…
The electrical transport properties of a bipolar InAs/GaSb system have been studied in magnetic field. The resistivity oscillates between insulating and metallic behaviour while the quantum Hall effect shows a digital character oscillating…
When quasiparticles move in condensed matters, the texture of their internal quantum structure as a function of position and momentum can give rise to Berry phases that have profound effects on materials properties. Seminal examples include…
A Mn4 single-molecule magnet displays asymmetric Berry-phase interference patterns in the transverse-field (HT) dependence of the magnetization tunneling probability when a longitudinal field (HL) is present, contrary to symmetric patterns…
The geometrical Berry phase is key to understanding the behaviour of quantum states under cyclic adiabatic evolution. When generalised to non-Hermitian systems with gain and loss, the Berry phase can become complex, and should modify not…
We have studied the magnetotransport properties of the metallic, p-type Sb2Te2Se which is a topological insulator. Magnetoresistance shows Shubnikov de Haas oscillations in fields above B=15 T. The maxima/minima positions of oscillations…
The effect of electronic band curvature, i.e. the deviation from parabolicity of electronic dispersion, on de Haas-van Alphen oscillations spectra is studied. Although the oscillations amplitude remain unaffected, it is demonstrated that…
We study the energy spectrum of magnons in a ferromagnet with topologically nontrivial magnetization profile. In the case of inhomogeneous magnetization corresponding to a metastable state of ferromagnet, the spin-wave equation of motion…
We study anisotropic lattice strips in the presence of a magnetic field in the quantum Hall effect regime. At specific magnetic fields, causing resonant Umklapp scattering, the system is gapped in the bulk and supports chiral edge states in…
We investigate the topological insulating states of the $p$-band systems in optical lattices induced by the onsite orbital angular momentum polarization, which exhibit gapless edge modes in the absence of Landau levels. This effect arises…
Electrons moving through a noncoplanar magnetic texture acquire a Berry phase, which can be described as an effective magnetic field. This effect is known as the topological Hall effect and has been observed in topological spin textures.…
The Mott-Ioffe-Regel limit sets the lower bound of carrier mean free path for coherent quasiparticle transport. Metallicity beyond this limit is of great interest because it is often closely related to quantum criticality and unconventional…
In Kondo insulator samarium hexaboride SmB$_6$, strong correlation and band hybridization lead to an insulating gap and a diverging resistance at low temperature. The resistance divergence ends at about 5 Kelvin, a behavior recently…
Co$_3$Sn$_2$S$_2$ is a ferromagnetic semi-metal with Weyl nodes in its band structure and a large anomalous Hall effect below its Curie temperature of 177 K. We present a detailed study of its Fermi surface and examine the relevance of the…
We discuss the recently achieved Bose-Einstein condensation for alkali-metal atoms in magnetic traps. The theoretically predicted low-energy collective oscillations of the condensate have been experimentally confirmed by laser imaging…
The de Haas-van Alphen (dHvA) signal arising from orbits on the $\pi$ Fermi surface sheet of the two-gap superconductor MgB$_2$ has been observed in the vortex state below $H_{c2}$. An extra attenuation of the dHvA signal, beyond those…