相关论文: Dynamical coupling and separation of multiple degr…
A coupled atomistic spin and lattice dynamics approach is developed which merges the dynamics of these two degrees of freedom into a single set of coupled equations of motion. The underlying microscopic model comprises local exchange…
Manipulating spin fluctuations with ultrafast laser pulses is a promising route to dynamically control collective phenomena in strongly correlated materials. However, understanding how photoexcited spin degrees of freedom evolve at a…
This work examines the effects of magnetic frustration due to competing ferromagnetic and antiferromagnetic Heisenberg interactions on the spin dynamics of the double-exchange model. When the local moments are non-colinear, a charge-density…
The coherent spin dynamics of electrons and holes are studied in a FA0.9Cs0.1PbI2.8Br0.2 perovskite bulk crystal, using time-resolved Kerr ellipticity in a two-color pump-probe scheme. The probe photon energy is tuned to the exciton…
We present a simplified model for the colossal magnetoresistance in doped manganites by exactly solving a double-exchange model (with Ising-like local spins) and quenched binary disorder within dynamical mean field theory. We examine the…
The electronic structure of perovskite manganese oxides is investigated in terms of a Kondo lattice model with ferromagnetic Hund coupling and antiferromagnetic exchange between $t_{2g}$-spins using a finite temperature diagonalization…
The photo-induced metal-insulator transition is studied by the numerical simulation of real-time quantum dynamics of a double-exchange model. The spatial and temporal evolutions of the system during the transition have been revealed…
We present results of a cross-disciplinary theoretical research at the interface of spin physics and hot-electron transport. A moderately strong electric field is assumed to provide the streaming regime where each free charge carrier, an…
We theoretically study the nuclear spin dynamics driven by electron transport and hyperfine interaction in an electrically-defined double quantum dot (DQD) in the Pauli-blockade regime. We derive a master-equation-based framework and show…
Ultrafast optical excitation is known to destabilize long-range order in correlated systems, yet experiments have also reported the emergence of metastable phases, in some cases with enhanced critical temperatures. The microscopic origin of…
In terms of the exact quantum master equation solution for open electronic systems, the coherent dynamics of two charge states described by two parallel quantum dots with one fully polarized electron on either dot is investigated in the…
Photo-excited charge dynamics of interacting charge-frustrated systems are studied using a spinless fermion model on an anisotropic triangular lattice. Real-time evolution of the system after irradiating a pump-photon pulse is analyzed by…
Photoinduced hidden phases are often observed in materials with intertwined orders. Understanding the formation of these non-thermal phases is challenging and requires a resolution of the cooperative interplay between different orders on…
Quantum dots are recognized as a suitable platform for studying thermodynamic phenomena involving single electronic charges and spins in nano-scale devices. However, such a thermodynamic system is usually driven by electron reservoirs at…
We report a thermally activated metastability in a GaAs double quantum dot exhibiting real-time charge switching in diamond shaped regions of the charge stability diagram. Accidental charge traps and sensor back action are excluded as the…
From a general model of the Mn oxides R_{1-x}A_{x}MnO_3, we derive an effective Hamiltonian in the low-energy subspace using the projection operator method, in which a novel coupling between the spin and orbital degrees of freedom is…
The (001) surface of La_{1-x}Ca_xMnO_3 system in various magnetic orderings is studied by first principle calculations. A general occurrence is that z^2 dangling bond charge -- which is ``invisible'' in the formal valence picture -- is…
Complex many-body interaction in perovskite manganites gives rise to a strong competition between ferromagnetic metallic and charge ordered phases with nanoscale electronic inhomogeneity and glassy behaviors. Investigating this glassy state…
The transition between different states in manganites can be driven by various external stimuli. Controlling these transitions with light opens the possibility to investigate the microscopic path through which they evolve. We performed…
The spin-charge coupled dynamics in a thin, magnetized metallic system are investigated. The effective driving force acting on the charge carriers is generated by a dynamical magnetic texture, which can be induced, e.g., by a magnetic…