Related papers: Spin nematic fluctuations near a spin-density-wave…
We investigate theoretically the Seebeck effect in materials close to a ferromagnetic quantum critical point to explain anomalous behaviour at low temperatures. It is found that the main effect of spin fluctuations is to enhance the…
Inelastic neutron scattering measurements have been performed on single crystals of the heavy fermion compound Ce$_{0.925}$La$_{0.075}$Ru$_{2}$Si$_{2}$ in broad energy [0.1, 9.5 meV] and temperature [40 mK, 294 K] ranges in order to address…
When the transition temperature of a continuous phase transition is tuned to absolute zero, new ordered phases and physical behaviour emerge in the vicinity of the resulting quantum critical point. Sr3Ru2O7 can be tuned through quantum…
The signature for a non-Fermi liquid behavior near a quantum phase transition has been observed in thermal and transport properties of many metallic systems at low temperatures. In the present work we consider specific examples of itinerant…
We study the effects of non-magnetic impurities on the phase diagram of a system of interacting electrons with a flat Fermi surface. The one-loop Wilsonian renormalization group flow of the angle dependent diffusion function…
We study pseudogap behavior in a metal near a spin density wave (SDW) instability due to thermal magnetic fluctuations. We consider the $t-t'$ Hubbard model on a square lattice at a finite doping, at intermediate coupling strength, and…
The high temperature limit of interacting spins is usually not associated with ordering or critical phenomena. Nevertheless, spontaneous fluctuations of a local spin polarization at equilibrium have nontrivial dynamics even in this limit.…
The increase in the resistivity with decreasing temperature followed by a drop by more than one order of magnitude is observed on the metallic side near the zero-magnetic-field metal-insulator transition in a strongly interacting…
An ensemble of spins oriented along the $z$ direction exhibits nonzero fluctuation in the transverse ($x$- and $y$-) components of the spin angular momentum in accordance with the uncertainty principle. When the spins obey a spin…
We report on numerically exact determinantal quantum Monte Carlo simulations of the onset of spin-density wave (SDW) order in itinerant electron systems captured by a sign-problem-free two-dimensional lattice model. Extensive measurements…
The incommensurate spin-density-wave (SDW) phase in (TMTTF)$_2$Br was investigated through transport measurements under pressure and magnetic fields parallel to the $c^{\ast}$ axis. For the incommensurate SDW phase of (TMTTF)$_2$Br…
Using Monte Carlo simulations with a tunable uniaxial strain, for the first time the nematic susceptibility of a model for the pnictides is calculated. The results are in good agreement with the experiments by J-H. Chu {\it et al.}, Science…
We study the thermal activation of spin fluctuations in dynamically-stable spinor Bose-Einstein condensates. We analyze the specific cases of a non-dipolar spin-1 condensate in m = 0, where thermal activation results from spin-changing…
While the spin dynamics of La$_{0.7}$Ca$_{0.3}$MnO$_3$ in the ferromagnetic phase are known to be unconventional, previous measurements have yielded contradictory results regarding the damping of spin wave excitations. Neutron spectroscopy…
By performing time-of-flight neutron scattering measurements on a large amount of single crystals of Sr$_2$RuO$_4$, we studied detailed structure of the imaginary part of the dynamic spin susceptibility over a wide range of phase space. In…
The dynamical spin susceptibility is studied in the magnetically-disordered phase of heavy-Fermion systems near the antiferromagnetic quantum phase transition. In the framework of the $S=1/2$ Kondo lattice model, we introduce a perturbative…
The origin of nematic order remains one of the major debates in iron-based superconductors. In theories based on spin nematicity, one major prediction is that the spin-spin correlation length at (0,$\pi$) should decrease with decreasing…
We revisit the problem of electrons on a square lattice below half filling close to an Ising-nematic quantum critical point. For Fermi surfaces with sufficiently strong antinodal nesting, the static nematic susceptibility is maximal at the…
The dynamical spin susceptibility is studied in the magnetically-disordered phase of heavy-Fermion systems near the antiferromagnetic quantum phase transition. In the framework of the $S=1/2$ Kondo lattice model, we introduce a perturbative…
In iron-based superconductors, a spin-density-wave (SDW) magnetic order is suppressed with doping and unconventional superconductivity appears in close proximity to the SDW instability. The optical response of the SDW order shows clear gap…