A5014809890- Quantum, superfluid, helium dynamics
- Cold Atom Physics and Bose-Einstein Condensates
- Atomic and Subatomic Physics Research
- Physics of Superconductivity and Magnetism
- Quantum and electron transport phenomena
- Dark Matter and Cosmic Phenomena
- Strong Light-Matter Interactions
- Superconducting Materials and Applications
- Advancements in Semiconductor Devices and Circuit Design
- Spacecraft and Cryogenic Technologies
- Plasmonic and Surface Plasmon Research
- Particle physics theoretical and experimental studies
- Methane Hydrates and Related Phenomena
- Mechanical and Optical Resonators
- High-pressure geophysics and materials
- Topological Materials and Phenomena
- Thermal Radiation and Cooling Technologies
- Photonic and Optical Devices
- Gyrotron and Vacuum Electronics Research
- Advanced Condensed Matter Physics
- Quantum-Dot Cellular Automata
- Nuclear Physics and Applications
- Acoustic Wave Resonator Technologies
- Quantum chaos and dynamical systems
- Phase Equilibria and Thermodynamics
Korea Advanced Institute of Science and Technology
2011-2024
Weizmann Institute of Science
2014
Hallym University
2013
The Center for Axion and Precision Physics Research at the Institute Basic Science is searching axion dark matter using ultralow temperature microwave resonators. We report exclusion of mass range $10.7126--10.7186\text{ }\text{ }\ensuremath{\mu}\mathrm{eV}$ with near Kim-Shifman-Vainshtein-Zakharov (KSVZ) coupling sensitivity $10.16--11.37\text{ about 9 times larger 90% confidence level. This first search result in these ranges. It also a resonator physical less than 40 mK.
The CAST-CAPP axion haloscope, operating at CERN inside the CAST dipole magnet, has searched for axions in 19.74 $\mu$eV to 22.47 mass range. detection concept follows Sikivie haloscope principle, where Dark Matter convert into photons within a resonator immersed magnetic field. is an array of four individual rectangular cavities inserted strong phase-matched maximize sensitivity. Here we report on data acquired 4124 h from 2019 2021. Each cavity equipped with fast frequency tuning mechanism...
Recently, exciton-polaritons in a semiconductor microcavity were found to condense into coherent ground state much like Bose-Einstein condensate and superfluid. They have become unique testbed for generating manipulating quantum vortices driven-dissipative Here, we generate exciton-polariton with non-resonant Laguerre-Gaussian (LG) optical beam verify the direct transfer of light's orbital angular momentum fluid. Quantized are spite large energy relaxation involved pumping. We identified...
We report an extensive high-sensitivity search for axion dark matter above 1 GHz at the Center Axion and Precision Physics Research (CAPP). The cavity resonant search, exploiting coupling between axions photons, explored frequency (mass) range of 1.025 (<a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mrow><a:mn>4.24</a:mn><a:mtext> </a:mtext><a:mtext> </a:mtext><a:mi mathvariant="normal">μ</a:mi><a:mi>eV</a:mi></a:mrow></a:math>) to 1.185 (<d:math...
Hybridizing a microwave mode with quantum state requires precise frequency matching of superconducting resonator and the corresponding object. However, fabrication always brings imperfections in geometry material properties, causing deviations from desired operating frequencies. An effective universal strategy for their resonant coupling is to tune resonator, as states like phonons are hardly tunable. Here, we demonstrate gate-tunable, titanium-nitride (TiN)-based resonators by implementing...
The superflow in solid helium was detected by a decrease the resonant period of torsional oscillator (TO) below 0.2 K. Recently, shear modulus has shown an unusual increase with striking resemblance to those TO anomaly. similarities have invigorated alternative nonsuperfluid explanations for period. Here, we report influence change on examine fundamental connection between two phenomena. that exhibits quantitatively different drive dependence is not susceptible elastic change, indicating...
There are a number of distinct signatures superfluids, one which is the appearance quantized vortices. have been some attempts to understand putative supersolid 4He in vortex framework, but no conclusive evidence that supports existence vortices has reported. Here, we investigate rotation velocity dependence torsional oscillation solid at various temperatures. The sweep reveals intriguing periodic staircaselike features below about 300 mK. staircase patterns show remarkable periodicity, and...
We report the direct observation of a single quantized vortex vanishing from microcavity exciton-polariton superfluid. Exciton-polariton vortices generated by nonresonant Laguerre-Gaussian optical pumping beam reveal themselves in energy-integrated emission image, representing multimode entity consisting ground- and excited states. From time-resolved spectroscopy measurements utilizing various sizes, we find that two lowest-energy states get populated compete with each other, manifested...
Nanomechanical resonances coupled to microwave cavities can be excited, measured, and controlled simultaneously using electromechanical back-action phenomena. Examples of these effects include sideband cooling amplification, which are commonly described through linear equations motion governed by an effective optomechanical Hamiltonian. However, this approximation is invalid when the pump-induced cavity field large enough trigger nonlinearities, resulting in phenomena like frequency combs....
Multi-valued logic gates, which can handle quaternary numbers as inputs, are developed by exploiting the ballistic transport properties of quantum point contacts in series. The principle a gate that finds minimum two number inputs is demonstrated. device scalable to allow multiple makes it possible find single operation. Also, half-adder for First, an adder adds up and outputs sum Second, express into digits [Carry (first digit) Sum (second digit)] All gates presented this paper be extended...
We report an extensive high-sensitivity search for axion dark matter above 1\,GHz at the Center Axion and Precision Physics Research (CAPP). The cavity resonant search, exploiting coupling between axions photons, explored frequency (mass) range of 1.025\,GHz (4.24\,$\mu$eV) to 1.185\,GHz (4.91\,$\mu$eV). have introduced a number innovations in this field, demonstrating practical approach optimizing all relevant parameters haloscopes, extending presently available technology. CAPP 12\,T...
We have investigated the non-classical response of solid 4He confined in porous gold set to torsional oscillation. When helium is grown rapidly, nearly 7% appears be decoupled from oscillation below about 200 mK. Dissipation at temperatures where decoupling shows maximum variation. In contrast, substantially reduced slowly helium. The dynamic was also studied by imposing a sudden increase amplitude Extended relaxation resonant period shift, suggesting emergence pinning low energy...
Topological superconductors are among the most actively studied materials these days. They a promising candidate for hosting Majorana fermions either on their boundaries or in vortex cores. Detecting one-dimensional (1D) edge current around periphery of 2D ${p}_{x}+i{p}_{y}$ superconductor would be hallmark signature topological superconductivity, but not amenable to electronic measurements due charge-neutral nature. Thermal conductivity measurements, such as thermal Hall effect,...
We reexamined the rotation-induced effect observed in solid $^{4}\mathrm{He}$ by using a rigid two-frequency torsional oscillator (TO). The previous rotation experiments reported suppression of ``nonclassical'' TO response that was interpreted as evidence irrotational bulk superfluidity $^{4}\mathrm{He}$. However, experiment employed nonrigid could amplify elastic contribution response. Thus, it is important to clarify if be attributed an unavoidable effect. In our TO, complicated nonlinear...
A free surface of a dilute ^{3}He-^{4}He liquid mixture is unique system where two Fermi liquids with distinct dimensions coexist: three-dimensional (3D) ^{3}He in the bulk and two-dimensional (2D) at surface. To investigate novel effect generated by interaction between liquids, mobility Wigner crystal electrons formed on studied. An anomalous enhancement mobility, compared case 3D 2D systems do not interact each other, observed. The explained nontrivial reflection quasiparticles from covered system.
Quantum point contacts (QPC) are a primary component in mesoscopic physics and have come to serve various purposes modern quantum devices. However, fabricating QPC that operates robustly under extreme conditions, such as high bias or magnetic fields, still remains an important challenge. As solution, we analyzed the trench-gated (t-QPC) has central gate addition split-gate structure used conventional QPCs (c-QPC). From simulation modelling, predicted t-QPC larger more even subband spacings...
Despite extensive experimental efforts over the past two decades, quest for Majorana fermions in superconductors remains inconclusive. We propose an method that can conclusively confirm, or rule out, existence of these quasiparticles: Firstly, we shift focus from superconductors, whose very topological nature is disputed, to unambiguous superfluid $^3$He. Secondly, identify interaction between surface waves and chiral current bulk a varying density. The proposed experiment provides path...
<title>Abstract</title> Despite extensive experimental efforts over the past two decades, quest for Majorana fermions in superconductors remains inconclusive. We propose an method that can conclusively confirm, or rule out, existence of these quasiparticles: Firstly, we shift focus from superconductors, whose very topological nature is disputed, to unambiguous superfluid helium-3. Secondly, identify interaction between surface waves and chiral current bulk a varying density. The proposed...
Transverse magnetic focusing (TMF) is a staple technique in mesoscopic physics, used to study quasiparticles manner akin mass spectrometry. However, the quantum nature of TMF has been difficult appreciate due several challenges addressing wavelike properties quasiparticles. Here, we report numerical solution and experimental demonstration wavefunction for multichannel case, implemented using point contacts two-dimensional electron gas. The wavefunctions could be understood as transverse...
It has been previously advocated that the presence of daily and annual modulations axion flux on Earth's surface may dramatically change strategy searches. The arguments were based so-called Axion Quark Nugget (AQN) dark matter model which was originally put forward to explain similarity visible cosmological densities $\Omega_{\rm dark}\sim \Omega_{\rm visible}$. In this framework, population galactic axions with mass $ 10^{-6} {\rm eV}\lesssim m_a\lesssim 10^{-3}{\rm eV}$ velocity $\langle...
Abstract The angular momentum carries crucial information on the physical nature of quantum matter. We propose and analyze MEMS gyroscope techniques suitable for measuring mesoscopic matter specimens at low temperatures. bear in mind that it is not always possible to implement mode-matched gyroscopes, which we will refer as degenerate maximal signal sensitivity these applications due constraints given by cryogenic environment types samples available experiments. Because analysis...
Through a series of transverse magnetic focusing experiments, we show that hot electrons in two-dimensional electron gas system undergo an ultrafast relaxation when generated by quantum dot (QD) instead point contact (QPC). We find here QPC were well described the non-interacting Fermi model for excitations up to 1.5 meV above level 7.44 meV, whereas QD exhibited energy loss quadratic excitation. The was sizeable fraction tested excitations, about 55%. With proposal are relaxed immediately...