Related papers: Terahertz-driven Local Dipolar Correlation in a Qu…
Recent terahertz-pump second-harmonic-generation(SHG)-probe measurements of quantum paraelectrics observed a significant long-lived non-oscillatory SHG component following an ultrafast resonant excitation of the soft mode, which was…
Recent experiments have demonstrated that light can induce a transition from the quantum paraelectric to the ferroelectric phase of SrTiO$_3$. Here, we investigate this terahertz field-induced ferroelectric phase transition by solving the…
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…
"Hidden phases" are metastable collective states of matter that are typically not accessible on equilibrium phase diagrams. These phases can host exotic properties in otherwise conventional materials and hence may enable novel functionality…
Coherent manipulation of lattice vibrations using ultrafast light pulses enables access to nonequilibrium 'hidden' phases with designed functionalities in quantum materials. However, expanding the understanding of nonlinear light-phonon…
I show that a nonequilibrium paraelectric to ferroelectric transition can be induced using midinfrared pulses. This relies on a quartic $lQ_{\textrm{l$_z$}}^2Q_{\textrm{h$_x$}}^2$ coupling between the lowest ($Q_{\textrm{l$_z$}}$) and…
Terahertz (THz) frequency range holds immense potential for high-speed data processing and signal manipulation. However, a fundamental challenge remains: the efficient and tunable control of THz electromagnetic fields. One promising…
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,…
Understanding surface collective dynamics in quantum materials is crucial for advancing quantum technologies. For example, surface phonon modes in quantum paraelectrics are thought to play an essential role in facilitating interfacial…
We investigate the role of polarization-photon coupling (specifically, polarization-oscillation-induced radiation electric field) in the excitation of ferroelectric thin films by an ultrafast terahertz (THz) electric-field pulse. Analytical…
Ultrafast coherent control of electric dipoles using strong terahertz (THz) pulses provides a means to discover hidden phases of materials and potentially leads to applications in high-speed electro-optic devices. The effectiveness of this…
THz-range dielectric spectroscopy and first-principle-based effective-Hamiltonian molecular dynamics simulations were employed to elucidate the dielectric response in the paraelectric phase of (Ba,Sr)TiO3 solid solutions. Analysis of the…
Combination of local heating and biasing at the tip-surface junction in temperature-assisted piezoresponse force microscopy (tPFM) opens the pathway for probing local temperature induced phase transitions in ferroics, exploring the…
Historically, the soft mode theory of ferroelectric phase transitions has been developed for the high-temperature (paraelectric) phase, where the phonon mode softens upon decreasing the temperature. In the low-temperature ferroelectric…
Ferroelectric materials offer unprecedented ultrafast responses and are of great interest for the development of new polarizable media under the influence of an electromagnetic field. Recent research efforts have demonstrated the role of…
Excitation, detection and control of coherent THz magnetic excitation in antiferromagnets are challenging problems that can be addressed using ever shorter laser pulses. We study experimentally excitation of magnetic dynamics at THz…
The symmetry breaking induced by the ferroelectric transition often triggers the emergence of topological electronic states such as Weyl fermions in ferroelectric-like metals/semimetals. Such strong coupling between the lattice deformation…
Motivated by recent experiments on pump-induced polar ordering in the quantum paraelectric SrTiO$_3$, we study a driven phonon system close to a second order phase transition. Analyzing its classical dynamics, we find that sufficiently…
High-frequency dielectric studies of Bi_0.85Nd_0.15FeO_3 ceramics performed betweeen 100 and 900 K reveal hardening of most polar phonons on cooling below antiferroelectric phase transition, which occurs near 600 K. Moreover, a strong THz…
Dynamical multiferroicity features entangled dynamic orders: fluctuating electric dipoles induce magnetization. Hence, the material with paraelectric fluctuations can develop magnetic signatures if dynamically driven. We identify the…