A5000287994- Advanced Condensed Matter Physics
- Magnetic and transport properties of perovskites and related materials
- Electronic and Structural Properties of Oxides
- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Multiferroics and related materials
- Topological Materials and Phenomena
- Physics of Superconductivity and Magnetism
- Ferroelectric and Piezoelectric Materials
- Iron-based superconductors research
- Graphene research and applications
- Magnetic properties of thin films
- Advanced Sensor and Energy Harvesting Materials
- Transition Metal Oxide Nanomaterials
- Machine Learning in Materials Science
- Nuclear materials and radiation effects
- Inorganic Chemistry and Materials
- High-pressure geophysics and materials
- Photorefractive and Nonlinear Optics
- Cold Atom Physics and Bose-Einstein Condensates
- Semiconductor materials and devices
- Dielectric materials and actuators
- Quantum, superfluid, helium dynamics
- Advanced Chemical Physics Studies
- Quantum and electron transport phenomena
Northwestern University
2016-2025
Bates College
2019
Drexel University
2013-2014
University of Cagliari
2009-2012
Istituto Nazionale di Fisica Nucleare, Sezione di Cagliari
2009
Elucidating the role of specific vibrational modes in spin lattice relaxation is a key step to designing room temperature qubits. We executed an experimental and theoretical study on series Cu 2+ qubits increase their operating temperature.
The combination of structural precision and reproducibility synthetic chemistry is perfectly suited for the creation chemical qubits, core units a quantum information science (QIS) system. By exploiting atomistic control inherent to chemistry, we address fundamental question how spin–spin distance between two qubits impacts electronic spin coherence. To achieve this goal, designed series molecules featuring spectrally distinct an early transition metal, Ti3+, late Cu2+ with increasing...
Abstract The emergence of magnetism in quantum materials creates a platform to realize spin-based applications spintronics, magnetic memory, and information science. A key unlocking new functionalities these is the discovery tunable coupling between spins other microscopic degrees freedom. We present evidence for interlayer magnetophononic layered topological insulator MnBi 2 Te 4 . Employing magneto-Raman spectroscopy, we observe anomalies phonon scattering intensities across field-driven...
Recent milestones in the synthesis and characterization of polar metals have contributed to a rapidly growing field research, rich materials physics potential applications. The burgeoning interest, however, has been accompanied by varied sometimes inconsistent terminology, inhibiting clear communication revealing fundamental tensions between theoretical descriptions microscopic models. authors review frontier research from perspectives theory, experiment, simulation, introduce uniform...
We present a variational pseudo self-interaction correction density functional approach (VPSIC) to the ab initio theoretical description of correlated solids and molecules. The generalizes previous nonvariational versions based on plane waves (pseudo correction) or atomic orbital (atomic correction). VPSIC provides well-defined total energies forces enables structural optimization dynamics, aside from providing high-quality electronic-structure-related properties as methods. A variety...
Noncentrosymmetric (NCS) phases are seldom seen in layered A2BO4 Ruddlesden-Popper (214 RP) oxides. In this work, we uncover the underlying crystallographic symmetry restrictions that enforce spatial parity operation of inversion and then subsequently show how to lift them achieve NCS structures. Simple octahedral distortions alone, while impacting electronic magnetic properties, insufficient. We using group theory condensation two distortion modes, which describe suitable unique or a...
We examine the electronic properties of newly discovered "ferroelectric metal" LiOsO3 combining density-functional and dynamical mean-field theories. show that material is close to a Mott transition correlations can be tuned engineer multiferroic state in 1/1 superlattice LiNbO3. use structure calculations predict (LiOsO3)1/(LiNbO3)1 exhibits strong coupling between magnetic ferroelectric degrees freedom with polarization 41.2 μC cm(-2), Curie temperature 927 K, Néel 379 K. Our results...
Polar domains arise in insulating ferroelectrics when free carriers are unable to fully screen surface-bound charges. Recently discovered binary and ternary polar metals exhibit broken inversion symmetry coexisting with electrons that might be expected suppress the electrostatic driving force for domain formation. Contrary this expectation, we report first direct observation of single crystals metal Ca3Ru2O7. By a combination mesoscale optical second-harmonic imaging atomic-resolution...
By using a combination of heteroepitaxial growth, structure refinement based on synchrotron x-ray diffraction and first-principles calculations, we show that the symmetry-protected Dirac line nodes in topological semimetallic perovskite SrIrO3 can be lifted simply by applying epitaxial constraints. In particular, gap opens without breaking Pbnm mirror symmetry. virtue symmetry-breaking analysis, demonstrate original symmetry protection is related to n-glide operation, which selectively...
The magnetic properties of the transition metal monoxides MnO and NiO are investigated at equilibrium under pressure via several advanced first-principles methods coupled with Heisenberg Hamiltonian MonteCarlo. comparative analysis involves two promising beyond-local density functionals approaches, namely hybrid functional theory recently developed variational pseudo-self-interaction correction method, implemented both plane-wave atomic-orbital basis sets. deliver a very satisfying...
Over 50 years ago, Anderson and Blount proposed that ferroelectric-like structural phase transitions may occur in metals, despite the expected screening of Coulomb interactions often drive polar transitions. Recently, theoretical treatments have suggested such require itinerant electrons be decoupled from soft transverse optical phonons responsible for order. However, this electron mechanism (DEM) has yet to experimentally observed. Here we utilize ultrafast spectroscopy uncover evidence DEM...
Magnetism in topological materials creates phases exhibiting quantized transport phenomena with potential technological applications. The emergence of such relies on strong interaction between localized spins and the bands, consequent formation an exchange gap. However, this remains experimentally unquantified intrinsic magnetic materials. Here, is quantified MnBi2 Te4 , a insulator antiferromagnetism. This achieved by optically exciting Bi-Te p states comprising bulk bands interrogating Mn...
We interpret via advanced ab initio calculations the multiple phase transitions observed recently in ultrathin LaNiO${}_{3}$/LaAlO${}_{3}$ superlattices. The ground state is insulating, weakly charge ordered, and antiferromagnetic due to concurrent structural distortion weak valency disproportionation. infer distinct around 50 K 110 K, respectively, from order moment disorder, a structurally dimerized insulator an undistorted metallic Pauli paramagnet (exhibiting cupratelike Fermi surface)....
Enhancing the performance of nanoscale ferroelectric (FE) field-effect transistors and FE capacitors for memory devices logic relies on miniaturizing metal electrode/ferroelectric area reducing thickness insulator. Although size reductions improve data retention, deliver lower voltage threshold switching, increase areal density, they also degrade functional electric polarization. There is a critical nanometer length tFE∗ below which polarization disappears owing to depolarizing field...
2D polymers (2DPs) are promising as structurally well-defined, permanently porous, organic semiconductors. However, 2DPs nearly always isolated closed shell species with limited charge carriers, which leads to low bulk conductivities. Here, the conductivity of two naphthalene diimide (NDI)-containing 2DP semiconductors is enhanced by controllably n-doping NDI units using cobaltocene (CoCp2 ). Optical and transient microwave spectroscopy reveal that both as-prepared NDI-containing...
A theoretical framework is outlined for calculating the spin-Chern number of topological Dirac semimetals and quantum spin Hall insulators lacking spin-conservation law gapless edge modes. Spin-charge separation quantized spin-pumping are probed by inserting a magnetic flux tube.
LiOsO3 is one of the first materials identified in recent literature as a “polar metal,” class that are simultaneously noncentrosymmetric and metallic. In this work, linear nonlinear optical susceptibility studied by means ellipsometry second harmonic generation (SHG). Strong birefringence observed using spectroscopic ellipsometry. The extracted from SHG polarimetry reveals tensor components same magnitude isostructural insulator LiNbO3, except component along polar axis d33 suppressed an...
The discovery of polar metals, bulk band conductors which combine broken inversion symmetry and metallic conductivity, has disrupted the long-standing assumption that order metallicity are incompatible. Despite recent progress, however, circumstances allow for this property convergence remain ambiguous. Here, we perform a first-principles analysis evolution in distortions perovskite ${\mathrm{BaTiO}}_{3}$ under electrostatic doping to ascertain dependencies acentricity electrical...
2D metal–organic frameworks provide insight into kagomé spin physics.