Related papers: Photoinduced Nonequilibrium Dynamics in Charge Ord…
We provide a theoretical framework to describe the nonequilibrium temporal dynamics of correlated electron systems for realistic system parameters and the consequent, often exponentially long time scales. It is based on an entirely…
Recent studies of pairing and charge order in materials such as FeSe, SrTiO$_3$, and 2H-NbSe$_2$ have suggested that momentum dependence of the electron-phonon coupling plays an important role in their properties. Initial attempts to study…
Quantitative knowledge of electron-phonon coupling is important for many applications as well as for the fundamental understanding of nonequilibrium relaxation processes. Time-resolved diffraction provides direct access to this knowledge…
Thermal fluctuations tend to destroy long-range phase correlations. Consequently, bosons in a lattice will undergo a transition from a phase-coherent superfluid as the temperature rises. Contrary to common intuition, however, we show that…
The out-of-equilibrium dynamics of electrons and phonons upon laser excitation are often described by the two-temperature model, which assumes that both subsystems are separately in thermal equilibrium. However, recent experiments show that…
Light-manipulation of correlated electronic phases in solids offers the tantalizing prospect of realizing electronic devices operating at the ultrafast time-scale. In this context, the experimental realization of non-equilibrium transitions…
We numerically investigate photo-responses of the charge ordered state upon stimuli of pulsed laser light, especially paying attention to the differences in the pulse width, whose shortness has been a key to experimentally realize large…
Aligning self-propelled particles undergo a nonequilibrium flocking transition from apolar to polar phases as their interactions become stronger. We propose a thermodynamically consistent lattice model, in which the internal state of the…
Bosonic gases coupled to a particle reservoir have proven to support a regime of operation where Bose-Einstein condensation coexists with unusually large particle-number fluctuations. Experimentally, this situation has been realized with…
The photoexcited dynamics of order parameter in Peierls chain is investigated by using a microscopic quantum theory in the limit where the hot electrons may establish themselves into a quasi-equilibrium state described by an effective…
We present Raman scattering studies of the structural and magnetic phases that accompany temperature- and field-dependent melting of charge- and orbital-order (COO) in La0.5Ca0.5MnO3 and La0.25Pr0.375Ca0.375MnO3. Our results show that…
Photoinduced melting of charge order is calculated by using the exact many-electron wave function coupled with classically treated phonons in the one-dimensional quarter-filled Hubbard model with Peierls and Holstein types of…
We investigated nonlinear conduction in bulk single crystals of VO2 with precise temperature control. Two distinct nonequilibrium phenomena were identified: a gradual reduction of the charge gap and a current-induced insulator-metal…
We study correlated electron states in frustrated geometry of a triangular lattice. The interplay of long range interactions and finite residual entropy of a classical system gives rise to unusual effects in equilibrium ordering as well as…
We theoretically study photoinduced magnetic phase transitions and their dynamical processes in the Kondo-lattice model on a cubic lattice. It is demonstrated that light irradiation gives rise to magnetic phase transitions from the…
This thesis deals with the study of dynamical properties of out-of-equilibrium quantum systems. We introduce in particular a general class of Spin-Boson models, which describe for example light-matter interaction or dissipative phenomena.…
Among the parameters determining the efficiency of an organic solar cell, the open-circuit voltage ($V_\text{OC}$) is the one with most room for improvement. Existing models for the description of $V_\text{OC}$ assume that photogenerated…
In the transient state of d-wave superconductors, we investigate the temporal variation of photoinduced changes in the superfluid weight. We derive the formula that relates the nonlinear response function to the nonequilibrium distribution…
High-harmonic generation (HHG) is a typical high-order nonlinear optical phenomenon and can be used to probe electronic structures of solids. Here, we investigate the temperature dependence of HHG from Pr_{0.6}Ca_{0.4}MnO_{3} in the range…
Electric, thermal and thermoelectric transport in correlated electron systems probe different aspects of the many-body dynamics, and thus provide complementary information. These are well studied in the low- and high-temperature limits,…