相关论文: Weak localization of magnons in a disordered two-d…
We study the roton-like dip in the magnon dispersion at the boundary of the Brillouin zone in the isotropic S=1/2 Heisenberg quantum antiferromagnet. This high-energy feature is sometimes seen as indication of a fractionalization of the…
We consider a magnetic impurity in the two-dimensional Heisenberg antifferomagnet with long range antiferromagnetic order. At low temperature the impurity magnetic susceptibility has a Curie term ($\propto 1/T$) and a logarithmic correction…
Motivated by the recent heat transport experiments in 2D antiferromagnets, such as La$_2$CuO$_4$, where the exchange coupling $J$ is larger than the Debye energy $\Theta_{\rm D}$, we discuss different types of relaxation processes for…
Layered van der Waals (vdW) magnets are prominent playgrounds for developing magnetoelectric, magneto-optic and spintronic devices. In spintronics, particularly in spincaloritronic applications, low thermal conductivity ($\kappa$) is highly…
We define a current-conserving approximation for the local conductivity tensor of a disordered system which includes the effects of weak localization. Using this approximation we show that the weak localization effect in conductance is not…
A formalism is developed to treat magnetic impurities in a Mott-Hubbard antiferromagnetic insulator within a representation involving multiple orbitals per site. Impurity scattering of magnons is found to be strong when the number of…
We study the magnetic field-dependence of the thermal conductivity due to magnetic excitations in frustrated spin-1/2 Heisenberg chains. Near the saturation field, the system is described by a dilute gas of weakly-interacting fermions…
We study the disordered Heisenberg spin chain, which exhibits many body localization at strong disorder, in the weak to moderate disorder regime. A continued fraction calculation of dynamical correlations is devised, using a variational…
We study the spectral and transport properties of magnons in a model of a disordered magnet called Mattis glass, at vanishing average magnetization. We find that in two dimensional space, the magnons are localized with the localization…
We present computational data on the thermal conductivity of nonlinear waves in disordered chains. Disorder induces Anderson localization for linear waves and results in a vanishing conductivity. Cubic nonlinearity restores normal…
Spontaneous intervalley coherence is suspected in several different graphene multilayer systems, but is difficult to confirm because of a paucity of convenient experimental signatures. Here we suggest that magneto-conductance features…
We have performed the first experimental investigation of quantum interference corrections to the conductivity of a bilayer graphene structure. A negative magnetoresistance - a signature of weak localisation - is observed at different…
The interplay of disorder and spin-fluctuation effects in a disordered antiferromagnet is studied. In the weak-disorder regime (W \le U), while the energy gap decreases rapidly with disorder, the sublattice magnetization, including quantum…
We explore the effect of a (non) magnetic impurity on the thermal transport of the spin-1/2 Heisenberg chain model. This unique system allows to probe Kondo-type phenomena in a prototype strongly correlated system. Using numerical…
We investigate magnetic polarons in two-dimensional strongly correlated electron systems, where conduction electrons interact with antiferromagnetically interacting localized spins. Starting from a basic model, we derive a simplified model…
It has become common knowledge that phonons can generate thermal Hall effect in a wide variety of materials, although the underlying mechanism is still controversial. We study longitudinal $\kappa_{xx}$ and transverse $\kappa_{xy}$ thermal…
The magnon thermal conductivity $\kappa_{\mathrm{mag}}$ of the spin ladders in $\rm Sr_{14}Cu_{24-x}Zn_xO_{41}$ has been investigated at low doping levels $x=0$, 0.125, 0.25, 0.5 and 0.75. The Zn-impurities generate nonmagnetic defects…
We study heat transport in quasi-one-dimensional spin-chain systems by considering the model of one-dimensional bosonic spin excitations interacting with three-dimensional phonons and impurities in the limit of weak spin-lattice coupling…
In $d$-electron systems, there can also be intricate interplay between Kondo coupling and magnetic interactions as that in $f$-electron systems, but the underlying mechanism remains elusive. Here, using inelastic neutron scattering, we…
Weak localization and weak anti-localization are quantum interference effects in quantum transport in a disordered electron system. Weak anti-localization enhances the conductivity and weak localization suppresses the conductivity with…