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Register a new userSpin structure factors of doped monolayer Germanene in the presence of spin-orbit coupling
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In this paper, we present a Kane-Mele model in the presence of magnetic field and next nearest neighbors hopping amplitudes for investigations of the spin susceptibilities of Germanene layer. Greens function approach has been implemented to find the behavior of dynamical spin susceptibilities of Germanene layer within linear response theoryand in the presence of magnetic field and spin-orbit coupling at finite temperature. Our results show the magnetic excitation mode for both longitudinal and transverse components of spin tends to higher frequencies with spin-orbit coupling strength. Moreover the frequency positions of sharp peaks in longitudinal dynamical spin susceptibility are not affected by variation of magnetic field while the peaks in transverse dynamical susceptibility moves to lower frequencies with magnetic field. The effects of electron doping on frequency behaviors of spin susceptibilities have been addressed in details. Finally the temperature dependence of static spin structure factors due to the effects of spin-orbit coupling, magnetic field and chemical potential has been studied.
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In this paper, we present a Kane-Mele model in the presence of magnetic field and next nearest neighbors hopping amplitudes for investigations the electronic and optical properties of monolayer Germanene. Specially, we address the dynamical conductivity of the structure as a function of photon frequency and in the presence of magnetic field and spin-orbit coupling at finite temperature. Using linear response theory and Greens function approach, the frequency dependence of optical conductivity has been obtained in the context of Kane-Mele model Hamiltonian. Our results show a finite Drude response at low frequency at non zero value for magnetic field in the presence of spin-orbit coupling. However Drude weight gets remarkable amount in the presence of electron doping. The thermal conductivity and specific heat increase with increasing the temperature at low amounts of temperature due to the increasing of thermal energy of charge carriers and excitation of them to the conduction bands. The results for Seebeck coefficient show the sign of thermopower is negative in the presence of spin-orbit coupling. Also we have studied the temperature dependence of electrical conductivity of Germanene monolayer due to both spin orbit coupling and magnetic field factors in details.
A hole injected into a Mott insulator will gain an internal structure as recently identified by exact numerics, which is characterized by a nontrivial quantum number whose nature is of central importance in understanding the Mott physics. In this work, we show that a spin texture associated with such an internal degree of freedom can explicitly manifest after the spin degeneracy is lifted by a emph{weak} Rashba spin-orbit coupling (SOC). It is described by an emergent angular momentum $J_{z}=pm3/2$ as shown by both exact diagonalization (ED) and variational Monte Carlo (VMC) calculations, which are in good agreement with each other at a finite size. In particular, as the internal structure such a spin texture is generally present in the hole composite even at high excited energies, such that a corresponding texture in momentum space, extending deep inside the Brillouin zone, can be directly probed by the spin-polarized angle-resolved photoemission spectroscopy (ARPES). This is in contrast to a Landau quasiparticle under the SOC, in which the spin texture induced by SOC will not be protected once the excited energy is larger than the weak SOC coupling strength, away from the Fermi energy. We point out that the spin texture due to the SOC should be monotonically enhanced with reducing spin-spin correlation length in the superconducting/pseudogap phase at finite doping. A brief discussion of a recent experiment of the spin-polarized ARPES will be made.
We investigate the 5d transition metal oxide BaOsO$_3$ within a combination of density functional theory (DFT) and dynamical mean-field theory (DMFT), using a matrix-product-state impurity solver. BaOsO$_3$ has 4 electrons in the t$_{2g}$ shell akin to ruthenates but stronger spin-orbit coupling (SOC) and is thus expected to reveal an interplay of Hunds metal behavior with SOC. We explore the paramagnetic phase diagram as a function of SOC and Hubbard interaction strengths, identifying metallic, band (van-Vleck) insulating and Mott insulating regions. At the physical values of the two couplings we find that BaOsO$_3$ is still situated inside the metallic region and has a moderate quasiparticle renormalization $m^*/m approx 2$; consistent with specific heat measurements. SOC plays an important role in suppressing electronic correlations (found in the vanishing SOC case) through the splitting of a van-Hove singularity (vHs) close to the Fermi energy, but is insufficient to push the material into an insulating van-Vleck regime. In spite of the strong effect of SOC, BaOsO$_3$ can be best pictured as a moderately correlated Hunds metal.
We explore the influence of contact interactions on a synthetically spin-orbit coupled system of two ultracold trapped atoms. Even though the system we consider is bosonic, we show that a regime exists in which the competition between the contact and spin-orbit interactions results in the emergence of a ground state that contains a significant contribution from the anti-symmetric spin state. This ground state is unique to few-particle systems and does not exist in the mean-field regime. The transition to this state is signalled by an inversion in the average momentum from being dominated by centre-of-mass momentum to relative momentum and also affects the global entanglement shared between the real- and pseudo-spin spaces. Indeed, competition between the interactions can also result in avoided crossings in the groundstate which further enhances these correlations. However, we find that correlations shared between the pseudo-spin states are strongly depressed due to the spin-orbit coupling and therefore the system does not contain spin-spin entanglement.
We use the Gutzwiller variational theory to investigate the electronic and the magnetic properties of fcc-Nickel. Our particular focus is on the effects of the spin-orbit coupling. Unlike standard relativistic band-structure theories, we reproduce the experimental magnetic moment direction and we explain the change of the Fermi-surface topology that occurs when the magnetic moment direction is rotated by an external magnetic field. The Fermi surface in our calculation deviates from early de-Haas--van-Alphen (dHvA) results. We attribute these discrepancies to an incorrect interpretation of the raw dHvA data.
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