相关论文: Terahertz-induced second-harmonic generation in qu…
Light-induced ferroelectricity in quantum paraelectrics is a new avenue of achieving dynamic stabilization of hidden orders in quantum materials. In this work, we explore the possibility of driving transient ferroelectric phase in the…
Understanding collective phenomena in quantum materials from first principles is a promising route toward engineering materials properties on demand and designing new functionalities. This work examines the quantum paraelectric state, an…
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 study electric field induced second harmonic generation (2HG) in the Kitaev model. This frustrated magnet hosts a quantum spin-liquid, featuring fractionalization in terms of mobile Majorana fermion and static $\mathbb{Z}_{2}$ flux-vison…
Nonlinear processes involving frequency-mixing of light fields set the basis for ultrafast coherent spectroscopy of collective modes in solids. In certain semimetals and semiconductors, generation of coherent phonon modes can occur by a…
Giant second-harmonic generation (SHG) in the terahertz (THz) frequency range is observed in a thin film of an s-wave superconductor NbN, where the time-reversal ($\mathcal{T}$-) and space-inversion ($\mathcal{P}$-) symmetries are…
We theoretically investigate the effects of the excitation frequency on the plateau of high-order terahertz sideband generation (HSG) in semiconductors driven by intense terahertz (THz) fields. We find that the plateau of the sideband…
We report terahertz (THz) second harmonic generation (SHG) in superconductors (SC) with inversion symmetric equilibrium states that forbid even-order nonlinearities. Such SHG signal is observed in single-pulse emission by periodic driving…
We report on far- and mid-infrared reflectivity of NdMnO3 from 4 K to 300K. Two main features are distinguished in the infrared spectra: active phonons in agreement with the expected for orthorhombic D2h 16-Pbnm (Z=4) space group remaining…
Recent experimental studies have demonstrated the possibility of utilizing strong terahertz pulses to manipulate individual ferroic orders on pico- and femtosecond timescales. Here, we extend these findings and showcase the simultaneous…
Superconductivity has been observed for the 2D electron gas (2DEG) at the interface of KTaO3 with other oxides, with a transition temperature about an order of magnitude higher than its 3d cousin SrTiO3. The superconducting transition…
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…
Achieving parametric excitation in an oscillating physical system involves periodically adjusting one of its parameters to modulate the oscillator's natural frequency. This phenomenon has been observed in numerous systems within physics and…
Intense, single-cycle terahertz (THz) pulses offer a promising approach for understanding and controlling the properties of a material on an ultrafast time scale. In particular, resonantly exciting phonons leads to a better understanding of…
Ultrafast optical control of quantum systems is an emerging field of physics. In particular, the possibility of light-driven superconductivity with ultrashort laser pulses has attracted much of attention. To identify non-equilibrium…
We present a microscopic model of the quantum paraelectric-ferroelectric phase transition with a focus on the influence of coupled fluctuating phonon modes. These may drive the continuous phase transition first order through a metaelectric…
We report on the observation of terahertz radiation in a non-centrosymmetric insulating oxide, paratellurite ($\alpha$-TeO$_2$) by irradiation of a femtosecond laser pulse at room temperature. In the power spectrum of the terahertz…
The emergence of collective order in matter is among the most fundamental and intriguing phenomena in physics. In recent years, the ultrafast dynamical control and creation of novel ordered states of matter not accessible in thermodynamic…
We study the nonlinear optical response in a superconducting NbN thin film with strong terahertz (THz)wave. Besides the expected third harmonic generation, we observe a new transient oscillation which softensin frequency with temperature…
The femtosecond optical pump-probe technique was used to study dynamics of photoexcited electrons and coherent optical phonons in transition metals Zn and Cd as a function of temperature and excitation level. The optical response in time…