391 citations · 765 across the 22 of their papers we have counts for
23 papers
Second-order Raman and anharmonic lattice dynamics in lead-halide perovskites
Chao Shen, Florian Kluibenschedl, Ayan A. Zhumekenov +4
We explore the microscopic origin of THz-driven lattice dynamics in methylammonium lead bromide CHNHPbBr using two-dimensional THz Kerr-effect spectroscopy. The analysi…
Alignment-free ultra-broadband parametric frequency conversion in lead-halide perovskites
Abhishek Shiva Kumar, Dusan Lorenc, Ayan A. Zhumekenov +2
Lead-halide perovskites were demonstrated to exhibit some of the largest known optical nonlinearities, yet their potential for frequency conversion remains largely untapped. Here w…
Nonlinear Terahertz Polaritonics in a Quantum Paraelectric
Chao Shen, Carla Verdi, Serafim Babkin +2
Terahertz (THz) frequency range holds immense potential for high-speed data processing and signal manipulation. However, a fundamental challenge remains: the efficient and tunable…
Using optical tweezers to simultaneously trap, charge and measure the charge of a microparticle in air
Andrea Stoellner, Isaac C. D. Lenton, Artem G. Volosniev +9
Optical tweezers are widely used as a highly sensitive tool to measure forces on micron-scale particles. One such application is the measurement of the electric charge of a particl…
Disentangling Electronic and Ionic Nonlinear Polarization Effects in the THz Kerr Response of LaAlO
Chao Shen, Maximilian Frenzel, Sebastian F. Maehrlein +1
Nonlinear responses to intense terahertz (THz) fields provide unique insights into complex dynamics of contemporary material systems. However, the interpretation of the obtained da…
Universal transparency and fine band structure near the Dirac point in HgTe quantum wells
V. Dziom, A. Shuvaev, J. Gospodaric +6
Spin-orbit coupling in thin HgTe quantum wells results in a relativistic-like electron band structure, making it a versatile solid state platform to observe and control non-trivial…
Spontaneous flexoelectricity in cubic lead-halide perovskite MAPbBr
Dmytro Rak, Dusan Lorenc, Ayan A. Zhumekenov +2
Lead-halide perovskites exhibit remarkable efficiency in photovoltaics, driven by exceptionally long carrier diffusion lengths and recombination times. Paradoxically, this performa…
Massive Dirac-Pauli physics in lead-halide perovskites
Abhishek Shiva Kumar, Mikhail Maslov, Mikhail Lemeshko +2
In standard quantum electrodynamics (QED), the so-called non-minimal (Pauli) coupling is suppressed for elementary particles and has no physical implications. Here, we show that th…
Observation of Analogue Dynamic Schwinger Effect and Non-Perturbative Light Sensing in Lead Halide Perovskites
Dusan Lorenc, Artem G. Volosniev, Ayan A. Zhumekenov +5
Dielectric breakdown of physical vacuum (Schwinger effect) is the textbook demonstration of compatibility of Relativity and Quantum theory. Although observing this effect is still…
Interferometric determination of intrinsic nonlinear Kerr index in lead-halide perovskites
Dusan Lorenc, Ayan Zhumekenov, Osman M. Bakr +1
Lead halide perovskites have recently been reported to demonstrate an exceptionally high nonlinear (Kerr) refractive index n of up to 10 cm/W in CHNHPbBr…
Dispersive effects in ultrafast non-linear phenomena
Dusan Lorenc, Zhanybek Alpichshev
It is a basic principle that an effect cannot come before the cause. Dispersive relations that follow from this fundamental fact have proven to be an indispensable tool in physics…
Mid-infrared Kerr index evaluation via cross-phase modulation with a near-infrared probe beam
Dusan Lorenc, Zhanybek Alpichshev
We propose a simple method to measure nonlinear Kerr refractive index in mid-infrared frequency range that avoids using sophisticated infrared detectors. Our approach is based on u…
Bond polarizability as a probe of local crystal fields in hybrid lead-halide perovskites
Yujing Wei, Artem G. Volosniev, Dusan Lorenc +4
A rotating organic cation and a dynamically disordered soft inorganic cage are the hallmark features of hybrid organic-inorganic lead-halide perovskites. Understanding the interpla…
Effective model for studying optical properties of lead-halide perovskites
Artem G. Volosniev, Abhishek Shiva Kumar, Dusan Lorenc +5
We use general symmetry-based arguments to construct an effective model suitable for studying optical properties of lead-halide perovskites. To build the model, we identify an atom…
Spin-Electric Coupling in Lead Halide Perovskites
Artem G. Volosniev, Abhishek Shiva Kumar, Dusan Lorenc +5
Lead-halide perovskites enjoy a number of remarkable optoelectronic properties. To explain their origin, it is necessary to study how electromagnetic fields interact with these sys…
Observation of exciton-exciton interaction mediated valley depolarization in monolayer MoSe
Fahad Mahmood, Zhanybek Alpichshev, Yi-Hsien Lee +2
The valley pseudospin in monolayer transition metal dichalcogenides (TMDs) has been proposed as a new way to manipulate information in various optoelectronic devices. This relies o…
Disorder enabled band structure engineering of a topological insulator surface
Yishuai Xu, Janet Chiu, Lin Miao +5
Three dimensional topological insulators are bulk insulators with topological electronic order that gives rise to conducting light-like surface states. These surface…
The origin of exciton mass in a frustrated Mott insulator NaIrO
Zhanybek Alpichshev, Edbert J. Sie, Fahad Mahmood +2
We use a three-pulse ultrafast optical spectroscopy to study the relaxation processes in a frustrated Mott insulator NaIrO. By being able to independently produce the out-o…
Ultrafast dynamics in the presence of antiferromagnetic correlations in electron-doped cuprate LaCeCuO
I. M. Vishik, F. Mahmood, Z. Alpichshev +3
We used femtosecond optical pump-probe spectroscopy to study the photoinduced change in reflectivity of thin films of the electron-doped cuprate LaCeCuO (LCCO) with…
Selective scattering between Floquet-Bloch and Volkov states in a topological insulator
Fahad Mahmood, Ching-Kit Chan, Zhanybek Alpichshev +4
The coherent optical manipulation of solids is emerging as a promising way to engineer novel quantum states of matter. The strong time periodic potential of intense laser light can…
Confinement-Deconfinement Transition as an Indication of Spin-Liquid-Type Behavior in NaIrO
Zhanybek Alpichshev, Fahad Mahmood, Gang Cao +1
We use ultrafast optical spectroscopy to observe binding of charged single-particle excitations (SE) in the magnetically frustrated Mott insulator NaIrO. Above the antiferr…
STM imaging of impurity resonances on BiSe
Zhanybek Alpichshev, Rudro R. Biswas, Alexander V. Balatsky +4
In this paper we present detailed study of the density of states near defects in BiSe. In particular, we present data on the commonly found triangular defects in this syste…
STM imaging of a bound state along a step on the surface of the topological insulator BiTe
Zhanybek Alpichshev, J. G. Analytis, J. -H. Chu +2
Detailed study of the LDOS associated with the surface-state-band near a step-edge of the strong topological-insulator Bi2Te3, reveal a one-dimensional bound state that runs parall…