A5005642968- Physics of Superconductivity and Magnetism
- Advanced Condensed Matter Physics
- Iron-based superconductors research
- Magnetic and transport properties of perovskites and related materials
- 2D Materials and Applications
- Cold Atom Physics and Bose-Einstein Condensates
- Quantum many-body systems
- Topological Materials and Phenomena
- Quantum and electron transport phenomena
- Theoretical and Computational Physics
- Magnetism in coordination complexes
- Quantum Computing Algorithms and Architecture
- Oral and Maxillofacial Pathology
- Rare-earth and actinide compounds
- Sarcoma Diagnosis and Treatment
- Neural Networks and Reservoir Computing
- Perovskite Materials and Applications
- Nonlinear Photonic Systems
- Organic and Molecular Conductors Research
- Quantum Information and Cryptography
- dental development and anomalies
- Tumors and Oncological Cases
- Rings, Modules, and Algebras
- Hydrology and Drought Analysis
- Dermatoglyphics and Human Traits
University of British Columbia
2024-2025
Oak Ridge National Laboratory
2016-2023
University of Tennessee at Knoxville
2016-2021
WWF-India
2021
Armed Forces Medical College
2017-2020
Fistulacure
2012-2017
Swami Devi Dyal Hospital and Dental College
2011-2017
Panjab University
2017
Indian Institute of Science Education and Research Kolkata
2017
Creative Commons
2014
Quantum computers hold the promise of solving certain problems that lie beyond reach conventional computers. Establishing this capability, especially for impactful and meaningful problems, remains a central challenge. Here we show superconducting quantum annealing processors can rapidly generate samples in close agreement with solutions Schrödinger equation. We demonstrate area-law scaling entanglement model quench dynamics two-, three- infinite-dimensional spin glasses, supporting observed...
Quantum computers hold the promise of solving certain problems that lie beyond reach conventional computers. Establishing this capability, especially for impactful and meaningful problems, remains a central challenge. One such problem is simulation nonequilibrium dynamics magnetic spin system quenched through quantum phase transition. State-of-the-art classical simulations demand resources grow exponentially with size. Here we show superconducting annealing processors can rapidly generate...
The Gangetic River System in Uttar Pradesh, India, supports 14 species of turtles. Excessive riverbedfarming has encroached on turtle habitat used for nesting and basking. To conserve threatened turtles the UpperGanga, an in-situ conservation program was initiated jointly by Pradesh Forest Department andWWF-India 2012 to engage community conservation. local riparian sensitizedand mobilized participate efforts. Turtles Ganga have religious significance arehonored community, which encourages...
Abstract Quantum error mitigation (QEM) presents a promising near-term approach to reducing errors when estimating expectation values in quantum computing. Here, we introduce QEM techniques tailored for annealing, using zero-noise extrapolation (ZNE). We implement ZNE through zero-temperature and zero-time extrapolations. The practical developed exploits the Kibble-Zurek mechanism so that only problem-Hamiltonian rescaling is required. conduct experimental investigations into critical...
Iron-based superconductors display a variety of magnetic phases originating in the competition between electronic, orbital, and spin degrees freedom. Previous theoretical investigations multi-orbital Hubbard model one dimension revealed existence an orbital-selective Mott phase (OSMP) with block order. Recent inelastic neutron scattering (INS) experiments on BaFe$_2$Se$_3$ ladder compound confirmed relevance block-OSMP. Moreover, powder INS spectrum reveled unexpected structure, containing...
Abstract Motivated by the recent experimental realization of minimal Kitaev chains using quantum dots, we investigate Majorana zero modes (MZM) in Y -shape wires. We solve associated models analytically at sweet spot ( t h = Δ) and derive exact form MZM wave-functions this geometry. observed exotic multi-site MZMs located near junction center, on nearby edge sites each leg. This result is important for potential braiding Majoranas performance -junctions made from arrays dots. Furthermore,...
We study non-local correlations in a three-orbital Hubbard model defined on an extended one-dimensional chain using determinant quantum Monte Carlo and density matrix renormalization group methods. focus parameter with robust Hund's coupling, which produces orbital selective Mott phase (OSMP) at intermediate values of the U, as well orbitally ordered ferromagnetic insulating state stronger coupling. An examination spin-correlation functions indicates that ordering occurs before onset...
We study ribbons of the dice two-dimensional lattice (that we call ``dice ladders'') known to have nontrivial topological properties, such as Chern numbers 2 [Wang and Ran, Phys. Rev. B 84, 241103(R) (2011)]. Our main results are two fold. (1) Analyzing tight-binding model in presence Rashba spin-orbit coupling an external magnetic field, observed that ladders qualitatively display properties similar their counterpart all way limit only legs short direction. This includes flat bands near...
Motivated by recent experimental progress in transition metal oxides with the ${\mathrm{K}}_{2}\mathrm{Ni}{\mathrm{F}}_{4}$ structure, we investigate magnetic and orbital ordering $\ensuremath{\alpha}\text{\ensuremath{-}}{\mathrm{Sr}}_{2}\mathrm{Cr}{\mathrm{O}}_{4}$. Using first-principles calculations, first derive a three-orbital Hubbard model, which reproduces ab initio band structure near Fermi level. The unique reverse splitting of ${t}_{2g}$ orbitals...
Abstract We present a method for computing the resonant inelastic x-ray scattering (RIXS) spectra in one-dimensional systems using density matrix renormalization group (DMRG) method. By DMRG to address this problem, we shift computational bottleneck from memory requirements associated with exact diagonalization (ED) calculations time algorithm. This approach is then used obtain RIXS on cluster sizes well beyond state-of-the-art ED techniques. Using new procedure, compute low-energy magnetic...
We employ a recently developed computational many-body technique to study for the first time half-filled Anderson-Hubbard model at finite temperature and arbitrary correlation U disorder V strengths. Interestingly, narrow zero metallic range induced by from Mott insulator expands with increasing in manner resembling quantum critical point. Our of resistivity scaling T^{α} this metal reveals non-Fermi liquid characteristics. Moreover, continuous dependence α on linear nearly quadratic is...
Abstract Lattice Wigner crystal states stabilized by long-range Coulomb interactions have recently been realized in two-dimensional moiré materials. We employ large-scale unrestricted Hartree-Fock techniques to unveil the magnetic phase diagrams of honeycomb lattice crystals. For three filling factors with largest charge gaps, $$n=2/3,1/2,1/3$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>n</mml:mi> <mml:mo>=</mml:mo> <mml:mn>2</mml:mn> <mml:mo>/</mml:mo>...
Using the density matrix renormalization group technique we study effect of spin-orbit coupling on a three-orbital Hubbard model in ${({t}_{2g})}^{4}$ sector and one dimension. Fixing Hund to robust value compatible with some multiorbital materials, present phase diagram varying $U$ $\ensuremath{\lambda}$, at zero temperature. Our results are shown be qualitatively similar those recently reported using dynamical mean-field theory higher dimensions, providing basis approximate many-body...
We studied a multi-orbital Hubbard model at half-filling for two and three orbitals per site on two-site cluster via full exact diagonalization, in wide range the onsite repulsion $U$, from weak to strong coupling, multiple ratios of Hund coupling $J_H$ $U$. The hopping matrix elements among were also varied extensively. At intermediate large we mapped results into Heisenberg model. For site, mapping is $S=1$ where by symmetry both nearest-neighbor $(\mathbf{S}_{i}\cdot\mathbf{S}_{j})$...
The magnetic and electronic phase diagram of a model for the quasi-one-dimensional alkali-metal iron selenide compound ${\mathrm{Na}}_{2}{\mathrm{FeSe}}_{2}$ is presented. novelty this material that valence ${\mathrm{Fe}}^{2+}$, contrary to most other iron-chain compounds with ${\mathrm{Fe}}^{3+}$. Using first-principles techniques, we developed three-orbital tight-binding reproduces ab initio band structure near Fermi level. Including Hubbard Hund couplings studying via density-matrix...
In strongly correlated electronic systems, several novel physical properties are induced by the orbital degree of freedom. particular, degeneracy near Fermi level leads to spontaneous symmetry breaking, such as nematic state in FeSe and ordering perovskite systems. Here, layered material CsVF$_4$, with a $3d^2$ configuration, was systematically studied using density functional theory multiorbital Hubbard model within Hatree-Fock approximation. Our results show that CsVF$_4$ should be...
Ab initio and continuum model studies predicted that the $\mathrm{\ensuremath{\Gamma}}$ valley transition metal dichalcogenide (TMD) homobilayers could simulate conventional multiorbital Hubbard on moir\'e honeycomb lattice. Here, we perform Wannierization starting from show a more general Kanamori-Hubbard emerges, beyond extensively studied standard model, which can be used to investigate many-body physics in TMD homobilayers. Using unrestricted Hartree-Fock Lanczos techniques, study these...
The condensation of spin-orbit-induced excitons in ${t}_{2g}^{4}$ electronic systems is attracting considerable attention. At large Hubbard $U$, antiferromagnetism was proposed to emerge from the Bose-Einstein Condensation (BEC) triplons (${J}_{\text{eff}}=1$). Here, we show that even at intermediate $U$ regimes, spin-orbit exciton possible leading also staggered magnetic order. canonical electron-hole excitations (excitons) transform into local triplon and this BEC strong coupling regime...
A recently introduced one-dimensional three-orbital Hubbard model displays orbital-selective Mott phases with exotic spin arrangements such as block states [J. Rincón et al., Phys. Rev. Lett. 112, 106405 (2014)PRLTAO0031-900710.1103/PhysRevLett.112.106405]. In this publication we show that the constrained-path quantum Monte Carlo (CPQMC) technique can accurately reproduce phase diagram of multiorbital model, paving way to future CPQMC studies in systems more challenging geometries, ladders...
This paper presents first-principles calculations that predict the stabilization of ferromagnetic long range order in two-dimensional compounds. The results show high degree cleavability for these layered compounds and should motivate future synthesize 2D magnetic applications.
Recent studies on ${\mathrm{Ba}}_{2}{\mathrm{CoO}}_{4}$ (BCO) and ${\mathrm{SrRuO}}_{3}$ (SRO) have unveiled a variety of intriguing phenomena, such as magnetic polarization oxygens, unexpected nodes in the spin density profile along bonds, unusual zigzag patterns triangular lattices. Here, using simple model calculations supplemented by functional theory we explain presence based antibonding character dominant singly occupied molecular orbitals transition metal (TM) to oxygen bonds. Our...
We report the results of a Hartree-Fock study applied to interacting electrons moving in two different bipartite lattices: dice and Lieb lattices, at half-filling. Both lattices develop ferrimagnetic order phase diagram $U$-$\lambda$, where $U$ is Hubbard onsite repulsion $\lambda$ Rashba spin-orbit coupling strength. Our main result observation an unexpected multitude topological phases for both lattices. All these are ferrimagnetic, but they differ among themselves their set six Chern...
Motivated by recent proposals of correlation induced insensitivity $d$-wave superconductors to impurities, we develop a simple pairing theory for these systems up moderate strength disorder. Our description implements the key ideas Anderson, originally proposed disordered $s$-wave superconductors, but in addition takes care inherent strong electronic repulsion compounds, as well disorder inhomogeneities. We first obtain self-consistent one-particle states, which capture effects exactly, and...