A5101702613- Magnetic properties of thin films
- Mechanical and Optical Resonators
- Diamond and Carbon-based Materials Research
- Graphene research and applications
- Quantum Electrodynamics and Casimir Effect
- Magnetic Properties and Applications
- Advanced Fiber Laser Technologies
- Quantum and electron transport phenomena
- Advanced Chemical Physics Studies
- Physics of Superconductivity and Magnetism
- Thermal Radiation and Cooling Technologies
- Photonic and Optical Devices
- Topological Materials and Phenomena
- Theoretical and Computational Physics
- Cold Atom Physics and Bose-Einstein Condensates
- Metal and Thin Film Mechanics
- Opinion Dynamics and Social Influence
- 2D Materials and Applications
- Magnetic Properties of Alloys
- Surface and Thin Film Phenomena
- Complex Network Analysis Techniques
- Advanced Thermodynamics and Statistical Mechanics
- Force Microscopy Techniques and Applications
- Crystallography and Radiation Phenomena
- Advanced MEMS and NEMS Technologies
Purdue University West Lafayette
2020-2023
Bauman Moscow State Technical University
2022
Stanford University
2021
Nanjing Normal University
2018-2019
Donghua University
2018
National Laboratory for Superconductivity
2017
Institute of Physics
2017
Chinese Academy of Sciences
2017
National University of Singapore
2007-2009
Singapore-MIT Alliance for Research and Technology
2007
The recently discovered spin defects in hexagonal boron nitride (hBN), a layered van der Waals material, have great potential quantum sensing. However, the photoluminescence and contrast of optically detected magnetic resonance (ODMR) hBN are relatively low so far, which limits their sensitivity. Here we report record-high ODMR 46$\%$ at room temperature, simultaneous enhancement by up to 17-fold surface plasmon gold-film microwave waveguide. Our results obtained with shallow vacancy...
Color centers in hexagonal boron nitride (hBN) have recently emerged as promising candidates for a new wave of quantum applications. Thanks to hBN's high stability and two-dimensional (2D) layered structure, color hBN can be readily integrated into nanophotonic plasmonic structures on chip. More importantly, the discovered optically addressable spin defects provide interface between photons electron spins sensing The most well-studied defects, negatively charged vacancy (VB−) been used...
Optically active spin defects in wide-bandgap materials have many potential applications quantum information and sensing. Spin two-dimensional layered van der Waals are just emerging to be investigated. Here we demonstrate that optically-addressable ensembles hexagonal boron nitride (hBN) can generated by femtosecond laser irradiation. We observe optically detected magnetic resonance (ODMR) of hBN created show the creation is strongly affected pulse energy laser. When number less than a few...
The recently discovered spin-active boron vacancy (V[Formula: see text]) defect center in hexagonal nitride (hBN) has high contrast optically-detected magnetic resonance (ODMR) at room-temperature, with a spin-triplet ground-state that shows promise as quantum sensor. Here we report temperature-dependent ODMR spectroscopy to probe spin within the orbital excited-state. Our experiments determine excited-state Hamiltonian, including room-temperature zero-field splitting of 2.1 GHz and g-factor...
This paper reports five-dimensional cooling and the nonlinear dynamics of a levitated nanoparticle in vacuum. Three center-of-mass motion modes two torsional vibration nanodumbbell linearly polarized laser are cooled simultaneously.
We numerically demonstrate that a planar slab made of magnetic Weyl semimetal (a class topological materials) can emit high-purity circularly polarized (CP) thermal radiation over broad mid- and long-wave infrared wavelength range for significant portion its emission solid angle. This effect fundamentally arises from the strong gyrotropy or nonreciprocity these materials, which primarily depends on momentum separation between nodes in band structure. clarify dependence this underlying...
The negatively charged boron vacancy (VB-) defect in hexagonal nitride (hBN) with optically addressable spin states has emerged due to its potential use quantum sensing. Remarkably, VB- preserves coherence when it is implanted at nanometer-scale distances from the hBN surface, potentially enabling ultrathin sensors. However, low efficiency hinders practical applications. Studies have reported improving overall of defects plasmonics; however, enhancements up 17 times date are relatively...
A levitated nonspherical nanoparticle in a vacuum is ideal for studying quantum rotations and an ultrasensitive torque detector probing fundamental particle-surface interactions. Here, we optically levitate silica nanodumbbell at 430 nm away from sapphire surface drive it to rotate GHz frequencies. The relative linear speed between the tip of reaches 1.4 km s-1 submicrometer separation. rotating near demonstrates sensitivity (5.0 ± 1.1) × 10-26 N m Hz-1/2 room temperature. Moreover, probed...
A remarkable prediction of quantum field theory is that there are electromagnetic fluctuations (virtual photons) everywhere, which leads to the intriguing Casimir effect. While force between two objects has been studied extensively for several decades, three not measured yet. Here, we report experimental demonstration an object under exerted by other simultaneously. Our system consists a micrometer-thick cantilever placed in microspheres, forming unique sphere-plate-sphere geometry. We also...
Public bike system (PBS) improves mobility in a healthy, emission-free, and congestion-reducing way. Various studies have examined the characteristics of PBS. Hitherto, there lacks quantitative analysis directed to effects newly emerged dockless bike-sharing (DBSS) on To fill this gap, paper takes Nanjing PBS as case study, explore changes usage after popularity DBSS at two levels, including user level station level. Results show that has greater effect weekdays than weekends, contrast with...
The coupling between a Co layer with in-plane easy axis of magnetization and Ni out-of-plane across nonmagnetic Cu spacer was studied by layer-resolved magnetic imaging. Photoelectron emission microscopy circular dichroism in soft x-ray absorption as the contrast mechanism were used for domain Crossed, wedge-shaped epitaxial layers 3.5--5.7 atomic monolayers (ML) 2.5--4.1 ML deposited onto 15 Ni/Cu(001). competition ferromagnetic interlayer uniaxial anisotropies two leads to noncollinear...
A Monte Carlo algorithm based on the hybrid Ising-DIFFOUR model is proposed to investigate phase transition in ferroelectromagnetic lattice which ferroelectric order and antiferromagnetic coexist below a certain temperature. The Ising spin moment displacement their susceptibilities as well, function of temperature for systems different magnetoelectric couplings, are simulated compared with mean-field approach. typical at Néel point Curie observed zero coupling. It demonstrated that weak...
We describe the effects of magnetostatic interactions and film thickness on switching properties reversal mechanisms periodic arrays elongated Ni80Fe20 thin rings. The magnetization process, field distributions transition fields between different equilibrium states are strongly affected by inter-ring spacing. For closely packed ring arrays, sharp transitions were observed from onion-to-vortex state due to collective In agreement with micromagnetic simulations, range stability vortex is...
Spin and orbital angular momentum of light plays a central role in quantum nanophotonics as well topological electrodynamics. Here, we show that the thermal radiation from finite-size bodies comprising nonreciprocal magneto-optical materials can exert spin torque even global equilibrium. Moving beyond paradigm near-field heat transfer, calculate radiative transfer between objects by combining Rytov's fluctuational electrodynamics with theory optical momentum. We prove single cubic particle...
Spin-resolved electronic and element-resolved magnetic properties of artificial fcc FeCu alloy thin films, grown epitaxially by pulsed-laser deposition in the ordered ${L1}_{0}$ phase on Cu(001), were studied spin-resolved valence-band photoemission soft x-ray circular dichroism. Valence-band reveals bands which are present due to reduced periodicity layered films. Dichroism measurements attest that Fe atoms all ferromagnetic, carry moments similar those ultrathin films Cu(001). The orbital...
The magnetic configurations and reversal processes in arrays of geometrically identical rounded rectangular Co rings have been investigated. Magnetic imaging reveals a range configurations, including diagonal onion, horseshoe vortex states. Reversal from the onion to state can occur via different routes involving domain wall motion within rings, mechanism depends on applied field orientation.
Optically active spin defects in solids are leading candidates for quantum sensing and networking. Recently, single were discovered hexagonal boron nitride (hBN), a layered van der Waals (vdW) material. Due to its two-dimensional structure, hBN allows be positioned closer target samples than three-dimensional crystals, making it ideal atomic-scale sensing, including nuclear magnetic resonance (NMR) of molecules. However, the chemical structures these remain unknown, detecting with an defect...
We report a significant modification of the magnetization reversal process in thin film rings with engineered defects created by focused ion beam. Using magnetic force microscopy, situ in-plane field, we observe that traditional onion-vortex transition occurs defect-free can be suppressed, and instead takes place through domain wall motion. have also investigated effects defect size, location, distribution on overall state. The results are explained terms pinning walls defects.