A5062839943- Physics of Superconductivity and Magnetism
- Advanced Condensed Matter Physics
- Magnetic and transport properties of perovskites and related materials
- Magnetic properties of thin films
- Theoretical and Computational Physics
- Iron-based superconductors research
- Multiferroics and related materials
- Electronic and Structural Properties of Oxides
- Rare-earth and actinide compounds
- Metal and Thin Film Mechanics
- Superconducting Materials and Applications
- Electrodeposition and Electroless Coatings
- Corrosion Behavior and Inhibition
- Superconductivity in MgB2 and Alloys
- High-pressure geophysics and materials
- Ferroelectric and Piezoelectric Materials
- Magnetic Properties and Applications
- Advanced Memory and Neural Computing
- ZnO doping and properties
- Advanced materials and composites
- Quantum and electron transport phenomena
- Magneto-Optical Properties and Applications
- Anodic Oxide Films and Nanostructures
- Semiconductor materials and devices
- Characterization and Applications of Magnetic Nanoparticles
Nanyang Technological University
2015-2024
Georgia Institute of Technology
2023-2024
National Technical University of Athens
2009-2023
Leibniz Institute for Solid State and Materials Research
2020
Technion – Israel Institute of Technology
2018
Data Storage Institute
2018
Agency for Science, Technology and Research
2018
Foundation for Research and Technology Hellas
2008-2017
University of Cambridge
2006-2017
University of Crete
2008-2017
Finding new collective electronic states in materials is one of the fundamental goals condensed matter physics. Atomic-scale superlattices formed from transition metal oxides are a particularly appealing hunting ground for In bulk form, exhibit remarkable range magnetic, superconducting, and multiferroic phases that great scientific interest potentially capable providing innovative energy, security, electronics medical technology platforms. may emerge at interfaces where dissimilar meet....
We introduce a new class of primitive building blocks for realizing quantum logic elements based on nanoscale magnetization textures called skyrmions. In skyrmion qubit, information is stored in the degree helicity, and logical states can be adjusted by electric magnetic fields, offering rich operation regime with high anharmonicity. By exploring large parameter space, we propose two qubit variants depending their quantized state. discuss appropriate microwave pulses required to generate...
Abstract In the ‘Beyond Moore’s Law’ era, with increasing edge intelligence, domain-specific computing embracing unconventional approaches will become increasingly prevalent. At same time, adopting a variety of nanotechnologies offer benefits in energy cost, computational speed, reduced footprint, cyber resilience, and processing power. The time is ripe for roadmap to guide future research, this collection aims fill that need. authors provide comprehensive neuromorphic using electron spins,...
The magnetic properties of manganite bilayers composed G-type antiferromagnetic (AFM) SrMnO${}_{3}$ and double-exchange ferromagnetic (FM) La${}_{0.7}$Sr${}_{0.3}$MnO${}_{3}$ are studied. A spin-glass state is observed as a result competing orders spin frustration at the La${}_{0.7}$Sr${}_{0.3}$MnO${}_{3}$/SrMnO${}_{3}$ interface. dependence irreversible temperature on cooling field follows Almeida-Thouless line. Although an ideal AFM featured with compensated configuration, exhibit exchange...
Abstract The topological Hall effect (THE) is the response to an emergent magnetic field, a manifestation of skyrmion Berry-phase. As magnitude THE in multilayers open question, it imperative develop comprehensive understanding skyrmions and other chiral textures, their electrical fingerprint. Here, using Hall-transport magnetic-imaging technologically viable multilayer film, we show that topological-Hall resistivity scales with isolated-skyrmion density over wide range temperature...
Abstract Spintronics exploit spin‐orbit coupling (SOC) to generate spin currents, torques, and, in the absence of inversion symmetry, Rashba and Dzyaloshinskii–Moriya interactions. The widely used magnetic materials, based on 3d metals such as Fe Co, possess a small SOC. To circumvent this shortcoming, common practice has been utilize large SOC nonmagnetic layers 5d heavy (HMs), Pt, currents turn, exert torques layers. Here, new class material architectures is introduced, excluding HMs, for...
We report experimental coupling of chiral magnetism and superconductivity in [IrFeCoPt]/Nb heterostructures. The stray field skyrmions with radius ≈50 nm is sufficient to nucleate antivortices a 25 Nb film, unique signatures the magnetization, critical current, flux dynamics, corroborated via simulations. also detect thermally tunable Rashba-Edelstein exchange isolated skyrmion phase. This realization strongly interacting skyrmion-(anti)vortex system opens path toward controllable...
The doping dependence of the superfluid density, r_s, high-Tc superconductors is usually considered in context Uemura relation, namely Tc proportional to rs, which generally assumed apply underdoped regime. We show that a modified plot Tc/Do versus where Do maximum d-wave gap at T=0, exhibits universal features point an alternative interpretation underlying physics. In region this canonical negative curvature expected when ground-state correlation competes with superconductivity (SC) by...
We study the low-energy spin fluctuations and superfluid density of a series pure Zn-substituted high-${T}_{c}$ superconductors (HTS) using muon relaxation ac-susceptibility techniques. At critical doping state, ${p}_{c},$ we find (i) simultaneous abrupt changes in magnetic spectrum superconducting ground state (ii) that slowing down becomes singular at $T=0.$ These results provide experimental evidence for quantum transition separates phase diagram HTS into two distinct states.
Up to now the crystallographic structure of magnetoelectric perovskite EuTiO3 was considered remain cubic down low temperature. Here we present high resolution synchrotron X-ray powder diffraction data showing existence a structural phase transition, from Pm-3m tetragonal I4/mcm, involving TiO6 octahedra tilting, in analogy case SrTiO3. The temperature evolution tilting angle indicates second-order transition with an estimated Tc=235K. This critical is well below recent anomaly reported by...
We report measurements of quasiparticle relaxation dynamics in the high-temperature superconductor (Ba,K)Fe2As2 optimally doped, underdoped, and undoped regimes. In underdoped sample, spin-density wave (SDW) order forms at approximately 85 K, followed by superconductivity 28 K. find emergence a normal-state that suppresses SDW temperature T{*} 60 K argue this is precursor to superconductivity.
Tungsten oxide and its associated bronzes (compounds of tungsten an alkali metal) are well known for their interesting optical electrical characteristics. We have modified the transport properties thin WO 3 films by electrolyte gating using both ionic liquids polymer electrolytes. able to tune resistivity gated film more than five orders magnitude, a clear insulator-to-metal transition is observed. To clarify doping mechanism, we performed series incisive operando experiments, ruling out...
A powerful approach to analysing quantum systems with dimensionality $d>1$ involves adding a weak coupling an array of one-dimensional (1D) chains. The resultant quasi-one-dimensional (q1D) can exhibit long-range order at low temperature, but are heavily influenced by interactions and disorder due their large anisotropies. Real q1D materials therefore ideal candidates not only provoke, test refine theories strongly correlated matter, also search for unusual emergent electronic phases. Here...
Magnetic skyrmions are promising as highly scalable, stable, and individually addressable elementary units for next-generation memory computing devices. However, their stability in the absence of external fields evolution upon confinement important open questions. The authors present zero-field stabilization room-temperature (RT) multilayered Ir/Fe($x$)/Co($y$)/Pt nanodots. They further show that skyrmion size can be modulated by a factor four---down to 50 nm---by systematically varying dot...
Magnetic nano-skyrmions develop quantized helicity excitations, and the quantum tunneling between possessing distinct helicities is indicative of nature these particles. Experimental methods capable nondestructively resolving aspects topological spin textures, their local dynamical response, functionality now promise practical device architectures for operations. With abilities to measure, engineer, control matter at atomic level, present opportunities translate ideas into solid-state...
Studies of magnetization dynamics have incessantly facilitated the discovery fundamentally novel physical phenomena, making steady headway in development magnetic and spintronics devices. The can be induced detected electrically, offering new functionalities advanced electronics at nanoscale. However, its scattering mechanism is still disputed. Understanding thin films especially important, because most devices are made from stacks multilayers with nanometer thickness. known to possess...
Abstract Non-collinear magnets exhibit a rich array of dynamic properties at microwave frequencies. They can host nanometre-scale topological textures known as skyrmions, whose spin resonances are expected to be highly sensitive their local magnetic environment. Here, we report resonance study an [Ir/Fe/Co/Pt] multilayer hosting Néel skyrmions room temperature. Experiments reveal two distinct the skyrmion phase during in-plane ac excitation, with frequencies between 6–12 GHz. Complementary...
The absolute values and temperature, T, dependence of the in-plane magnetic penetration depth ${\mathrm{La}}_{2\ensuremath{-}x}{\mathrm{Sr}}_{x}{\mathrm{CuO}}_{4}$ ${\mathrm{HgBa}}_{2}{\mathrm{CuO}}_{4+\ensuremath{\delta}}$ have been measured as a function carrier concentration. We find that superfluid density ${\ensuremath{\rho}}_{s}$ changes substantially systematically with doping. ${\ensuremath{\rho}}_{s}(0)$ are closely linked to available low-energy spectral weight determined by...
The relationship between the superconducting energy gap and critical temperature ${T}_{c}$ in high- superconductors is discussed. By examining carefully some of most recent low data penetration depth, angle resolved photoemission, tunneling spectroscopy measurements, we conclude that amplitude at $d$-wave nodes scales with ${T}_{c}$. This scaling behavior holds independent carrier concentration although underdoped regime maximum does not scale