A5008439042- Physics of Superconductivity and Magnetism
- Advanced Condensed Matter Physics
- Magnetic and transport properties of perovskites and related materials
- Theoretical and Computational Physics
- Quantum and electron transport phenomena
- Quantum many-body systems
- Magnetic properties of thin films
- Protein Structure and Dynamics
- Molecular spectroscopy and chirality
- Quantum-Dot Cellular Automata
- Rare-earth and actinide compounds
- Organic and Molecular Conductors Research
- Cold Atom Physics and Bose-Einstein Condensates
- Magnetism in coordination complexes
- Algebraic structures and combinatorial models
- Carbon Nanotubes in Composites
- 2D Materials and Applications
- Advanced Thermoelectric Materials and Devices
- Electronic and Structural Properties of Oxides
- Enzyme Structure and Function
- Mass Spectrometry Techniques and Applications
- Mechanical and Optical Resonators
- Ferroelectric and Piezoelectric Materials
Brookhaven National Laboratory
2024-2025
ETH Zurich
2018-2021
Skolkovo Institute of Science and Technology
2016-2019
Abstract Topotactic reduction of perovskite oxides offers a powerful approach for discovering novel phenomena, such as superconducting infinite‐layer nickelates and polar metallicity, is commonly accompanied by the emergence multiple valence states and/or complex crystal fields transition metals. However, understanding interplay between chemistry, electronic structure, physical properties at spin‐ orbital‐resolved levels in these reduced systems remains elusive. Here, x‐ray absorption...
By means of inelastic neutron scattering we investigate finite temperature dynamics in the quantum spin ladder compound (C$_5$H$_{12}$N)$_2$CuBr$_4$ (BPCB) near magnetic field induced critical point with dynamical exponent $z=2$. We observe universal finite-temperature scaling transverse local dynamic structure factor spectacular quantitative agreement long-standing theoretical predictions. At same time, already at rather low temperatures, strong non-universal longitudinal fluctuations. To...
We report the magnetic and calorimetric measurements in single crystal samples of square lattice $J_{1}-J_{2}$ quantum antiferromagnet BaCdVO(PO$_4$)$_2$. An investigation scaling magnetization reveals a "dimensionality reduction" indicative strong degree geometric frustration. Below characteristic temperature $T^{\ast}\simeq150$~mK we observe emergence an additional strongly fluctuating phase close to full saturation. It is separated from magnetically ordered state by first- second-order...
Magnetization, magnetocaloric, calorimetric, neutron and X-ray diffraction inelastic scattering measurements are performed on single crystals of BaCdVO(PO$_4$)$_2$. The low-temperature crystal structure is found to be a lower symmetry than previously assumed. result more complicated model spin Hamiltonian, which we infer from the wave dispersion spectrum. main finding novel state emerges in high magnetic fields after antiferromagnetic order terminated at $H_{c1}\simeq 4.0$ T. It distinct...
Superconductivity in infinite layer nickelates ${\mathrm{Nd}}_{1\ensuremath{-}x}{\mathrm{Sr}}_{x}{\mathrm{NiO}}_{2}$ has so far been achieved only thin films, raising questions on the role of substrates and interfaces. Given challenges associated with their synthesis it is imperative to identify intrinsic properties. We use resonant inelastic x-ray scattering investigate influence ${\mathrm{SrTiO}}_{3}$ capping excitations ($x=0$ 0.2). Spin are observed parent 20% doped regardless capping,...
No material perfectly realizes the frustrated quantum ferro-antiferromagnetic Heisenberg model on a square lattice, but BaCdVO(PO${}_{4}$)${}_{2}$ comes close. Here, authors perform neutron spectroscopy measurements in high magnetic fields to determine an appropriate spin Hamiltonian for this system. They overcome numerous technical difficulties, such as required ${}^{114}$Cd enrichment experiments and complex sample mosaic. The results will help understand previously discovered...
We introduce a microscopic model aimed at describing the behavior of fermionic excitations in background magnetic texture called ``spin-vortex checkerboard.'' This was proposed previously as possible alternative to stripes interpret experimental phenomenology spin and charge modulations 1/8-doped lanthanum cuprates. The involves two kinds interacting residing spin-rich spin-poor regions modulated structure. It is generalization another developed earlier for so-called ``grid principal terms...
Calmodulin (CaM) protein plays a very crucial role in the calcium signaling inside eukaryotic cell structure [1, 2]. It can also bind to other proteins/targets and facilitate various activities [3, 4]. Temperature dependent conformation changes CaM are studied with extensive molecular dynamics simulations. The quantitative comparison of simulation data forms experimental results probing different aspects folding process robust assessment accuracy calculations. provide detailed structural...
Understanding the complex ground state of van der Waals (vdW) magnets is essential for designing new materials and devices that leverage these platforms. Here, we investigate a two-dimensional vdW ferromagnet -- Fe$_5$GeTe$_2$-- with one highest reported Curie temperatures, to elucidate its magnetic excitations charge order. Using Fe $L_3 - $edge resonant inelastic x-ray scattering, find dual character excitations, consisting coherent magnon continuum, similar what sister compound...
Superconductivity in infinite layer nickelates Nd1-xSrxNiO2 has so far been achieved only thin films raising questions on the role of substrates and interfaces. Given challenges associated with their synthesis it is imperative to identify intrinsic properties. We use Resonant Inelastic X-ray Scattering (RIXS) investigate influence SrTiO3 capping excitations (x = 0 0.2). Spin are observed parent 20% doped regardless capping, proving that magnetism infinite-layer appears a significant fraction...
The $S=1/2$ spin ladder compound ${({\mathrm{C}}_{5}{\mathrm{H}}_{12}\mathrm{N})}_{2}{\mathrm{CuBr}}_{4}$ (BPCB) is studied by means of high-resolution inelastic neutron scattering. In agreement with previous studies we find a band triplet excitations gap $\ensuremath{\sim}0.8$ meV and bandwidth $\ensuremath{\sim}0.6$ meV. addition, observe distinct splitting the $50(1)\phantom{\rule{4pt}{0ex}}\ensuremath{\mu}\mathrm{eV}$ or $40(2)\phantom{\rule{4pt}{0ex}}\ensuremath{\mu}\mathrm{eV}$ at...