相关论文: Equilibrium non-linear phononics by electric field…
We study the effect of a terahertz field-driven single cavity mode for ultrafast control of a fermion chain with dissipation-induced nonlinearity and quadratic coupling to an infrared-active phonon mode. Without photon loss from the cavity,…
External coherent fields can drive quantum materials into non-equilibrium states, revealing exotic properties that are unattainable under equilibrium conditions -- an approach known as ``Floquet engineering.'' While optical lasers have…
A Terahertz (THz) laser with strong strength could excite more than one phonons and induce a transient lattice distortion termed as nonlinear phononics. This process allows dynamic control of various physical properties, including…
Coupling tailored electromagnetic fluctuations to materials provides a resource for controlling correlated quantum matter. By structuring the frequency, spatial, and modal distribution of fluctuations through a new generation of cavity…
Ferrons are quantum excitations of electric polarization in ferroelectrics and electric analogues of magnons but have lacked direct experimental verification at room temperature. We harness the coupling of soft phonons and ferroelectric…
Coherent control of quantum materials has progressed along two major fronts: nonlinear phononics, which reshapes lattices to induce emergent states, and Floquet engineering, which tailors electronic band reconstruction via time-periodic…
Femtosecond laser excitation of solid-state systems creates non-equilibrium hot electrons that cool down by transferring their energy to other degrees of freedom and ultimately to lattice vibrations of the solid. By combining ab initio…
Orbitally ordered states exhibit unique features which make them a promising platform for exploring the ultrafast dynamics of long-range order in solids: Their free energy typically has multiple discrete minima, and electric laser fields or…
Intense terahertz (THz) pulses induce transient inversion-symmetry breaking in quantum paraelectric SrTiO$_3$, yet the underlying mechanism remains controversial. Using fields up to $\sim$1.1 MV/cm, we reveal spatially inhomogeneous…
Similar to other perovskites in its family, $\mathrm{SrTiO_{3}}$ exhibits a significant softening of the ferroelectric mode with decreasing temperature, a behavior that typically heralds the onset of a ferroelectric transition. However,…
Light fields at THz and mid-infrared frequencies allow for the direct excitation of collective modes in condensed matter, which can be driven to large amplitudes. For example, excitation of the crystal lattice, has been shown to stimulate…
Exciting atomic oscillations with light is a powerful technique to control the electronic properties of materials, leading to remarkable phenomena such as light-induced superconductivity and ultrafast insulator to metal transitions. Here we…
Ultrafast perturbations offer a unique tool to manipulate correlated systems due to their ability to promote transient behaviors with no equilibrium counterpart. A widely employed strategy is the excitation of coherent optical phonons, as…
A resonantly excited coherent phonon leads to a periodic oscillation of the atomic lattice in a crystal structure bringing the material into a non-equilibrium electronic configuration. Periodically oscillating quantum systems can be…
We theoretically investigate nonequilibrium spin fluctuations in a ferromagnet induced by a light pulse. Using a Lindblad equation consistent with the Landau-Lifshitz-Gilbert equation, we compute the autocorrelation function of…
Negative nonlinear electron-phonon coupling involving an infrared-active phonon mode can lead to an instability towards the formation of a polar lattice distortion with ferrielectric (FE) moments accompanied by an electronic charge-density…
We discuss intrinsic mechanisms of nonequilibrium excess noise in superconducting devices and transition edge sensors. In particular, we present an overview of fluctuation-driven contributions to the current noise in the vicinity of the…
Identifying the microscopic nature of non-equilibrium energy transfer mechanisms among electronic, spin and lattice degrees of freedom is central for understanding ultrafast phenomena such as manipulating magnetism on the femtosecond…
We examine theoretically a possibility of ferroelectricity caused by electronic charge order without inversion symmetry, motivated by layered iron oxides. Quantum electronic models in a paired-triangular lattice are analyzed by utilizing…
Controlling the functional properties of quantum materials with light has emerged as a frontier of condensed-matter physics, leading to the discovery of various light-induced phases of matter, such as superconductivity, ferroelectricity,…