Magnetostriction of Pseudobinary Compounds Pr_(0.15)Tb_xDy_(0.85-x)Fe_2(x=0 to 0.85)

The compound ingots of Pr0.15TbxDy0.85-xFe2 (x=0 to 0.85) were prepared by arc melting in a water Cu boat using arc furnace under a purified Ar atmosphere. Appropriate annealing (850℃, 100 h) can obtain single Laves phase compound. The magnetostriction for these systems will rise obviously when partially substituted Tb or Dy by Pr.

Acceleration of Protons from a Double-Layer or Multi-Ion-Mixed Foil Irradiated by Ultraintense Lasers

Acceleration of protons by the radiation pressure of a circularly polarized laser pulse with the intensity up to 1021 W/cm^2 from a double-layer or multi-ion-mixed thin foil is investigated by two-dimensional particle-in-cell simulations. The double-layer foil is composed of a heavy ion layer and a proton layer. It is found that the radiation pressure acceleration can be classified into three regimes according to the laser intensity due to the different critical intensities for laser transparency with different ion species. When the laser intensity is moderately high, the laser pushes the electrons neither so slowly nor so quickly that the protons can catch up with the electrons, while the heavy ions cannot. Therefore, the protons can be accelerated efficiently. The proton beam generated from the double-layer foil is of better quality and higher energy than that from a pure proton foil with the same areal electron density. When the laser intensity is relatively low, both the protons and heavy ions are accelerated together, which is not favorable to the proton acceleration. When the laser intensity is relatively high, neither the heavy ions nor the protons can be accelerated efficiently due to the laser transparency through the target.

Processing and Characterization of Bulk FeSe

We investigated the effect of processing conditions on the structure and physical properties of the polycrystalline samples of Ca0.8Fe2Se2 prepared via solid state reaction. X-ray diffraction showed that the main phase became FeSe when the sintering temperature increased above 350 ℃. The temperature dependence of magnetization （M-T curves） recorded in zero-field-cooled mode by SQUID magnetometer showed some bumps at around 120 K to 140 K. These bumps moved to lower temperatures when the processing temperature increased above 550 ℃. On the other hand, pure FeSe materials produced at 900 ℃ for 24 h showed a sharp superconducting transition Tconset = 8.16 K and the critical current density of 6,252 A/cm2 at 5 K, self-field. SEM results indicated an enhanced grain connectivity.

Observation of Nearly Quantized Majorana Conductance Plateau in an Iron-based Superconductor

In 1937,Ettore Majorana,an Italian physicist,predicted an elementary particle called the Majorana Fermion,for which the particle is its own anti-particle.The Majorana Fermion in condensed matter physics is also known as the Majorana zero mode.Because Majorana zero modes obey non-Abel statistics,it holds a great promise for the realization of topological quantum computing,which has attracted widespread interest.

Observation of Zeeman splitting effect in a laser-driven coil

The Zeeman splitting effect is observed in a strong magnetic field generated by a laser-driven coil.The expanding plasma from the coil wire surface is concentrated at the coil center and interacts with the simultaneously generated magnetic field.The Cu I spectral lines at wavelengths of 510.5541,515.3235,and 521.8202 nm are detected and analyzed.The splittings of spectral lines are used to estimate the magnetic field strength at the coil center as∼31.4±15.7 T at a laser intensity of∼5.6310^(15) W/cm^(2),which agrees well with measurements using a B-dot probe.Some other plasma parameters of the central plasma disk are also studied.The temperature is evaluated from the Cu I spectral line intensity ratio,while the electron density is estimated from the Stark broadening effect.

Nano-Kirigami： A Nanoscale＂Paper-cut＂ Developed For 3D Intelligent Nanofabrication

Kirigami is one of the most traditional Chinese arts(named"paper-cuts"or"jianzhi")that has been widely used in window decorations,gift cards,festivals,ceremonies,etc.Through cutting and folding flat objects into 3D shapes,the knowledge of kirigami has recently aroused tremendous interests in both sciences and technologies,including deployable designs of solar arrays,biomedical devices and micro-/

Progress in Superconducting Quantum Computation: Quantum Simulation of Dynamical Phase Transitions

Quantum simulation uses a controllable quantum system to mimic complex systems or solve intractable problems,among which the non-equilibrium problems of quantum many-body systems have attracted wide research interest since they are hard to simulate using classical computers.Instead,popular quantum simulators,such as superconducting circuits,can provide insights into these problems.

Confinement Leads to Spatially Oscillatory Collective Motion of Chiral Active Matter

Active matter consisting of self-propelling units,e.g.bacterial solutions and self-driven colloids,is an important class of soft matter systems.Due to its inherent out-of-equilibrium nature,active matter often exliibits exotic behaviors and has potential applications in microdevices and smart materials.

Monte Carlo Study Reveals the Parent State of Quantum Phases

Numerical simulations provide the first concrete evidence of 2D (U1) deconfined matter, an exotic phase whose existence has been pursued by both condensed-matter and high-energy physicists. An international research team, led by Prof. MENG Ziyang from the Institute of Physics (IOP), Chinese Academy of Sciences (CAS) and comprised of Dr. XU Xiaoyan from Hong Kong University of Science and Technology, Associate Prof. QI Yang from Fudan University, Assistant Prof.

Quantum Phases of SrCu2(BO3)2 from High-Pressure Thermodynamics

In recent years,theoretical proposals for exotic states in quantum magnets are developing very rapidly,but many of these intriguing quantum phases and transitions have been difficult to realize experimentally.One class of such states is the valence bond solid,in which spins entangle locally and form symmetry-breaking singlet patterns.Signatures of a state with four-spin singlets were recently detected in the two-dimensional(2D)quantum magnet SrCu2(BO3)2 under high pressure.

Scientists Discover Rydberg Moiré Excitons

The Rydberg state is widely present in a variety of physical platforms such as atoms,molecules,and solids.In particular,the Rydberg excitons are highly excited Coulomb bound states of electronhole pairs,first discovered in the semiconductor material Cu2O in the 1950s.Their solid-state nature,in conjunction with the large dipole moments,strong mutual interactions,and significantly enhanced interactions with the surroundings,holds promises for a wide range of applications in sensing,quantum optics,and quantum simulation.However,compared with their atomic counterparts,namely Rydberg atoms that have been widely explored in recent years,the exploitation of Rydberg excitons is far from reaching their full potential.

Scientists Reveal“Magic Boron Clusters”on Monolayer Borophene

Boron,a chemical element located adjacent to carbon in the periodic table,has one less electron than carbon.This electron deficiency results in its strong bonding ability and diverse boron polymorphs.Despite their variations,all boron polymorphs have B12 clusters as their building blocks,which possess an icosahedral cage structure.Nonetheless,research combining experimental and theoretical approaches has revealed that small boron clusters in the gas phase,such as Bn(n=3 to 12,36),are planar or quasiplanar.This feature has enabled the possibility of twodimensional(2D)boron,also known as borophene.The unique properties of borophene,such as its mechanical flexibility,metallic Dirac fermions,and superconductivity,have generated significant experimental and theoretical interest.

Electromagnetic Emission from Laser Wakefields in Magnetized Underdense Plasmas

A wakefield driven by a short intense laser pulse in a perpendicularly magnetized underdense plasma is studied analytically and numerically for both weakly relativistic and highly relativistic situations. Owing to the DC magnetic field, a transverse component of the electric fields associated with the wakefield appears, while the longitudinal wave is not greatly affected by the magnetic field up to 22 Tesla. Moreover, the scaling law of the transverse field versus the longitudinal field is derived. One-dimensional particle-in-cell simulation results confirm the analytical results. Wakefield transmission through the plasma-vacuum boundary, where electromagnetic emission into vacuum occurs, is also investigated numerically. These results are useful for the generation of terahertz radiation and the diagnosis of laser wakefields.

Commissioning and first results from the new 2×100 TW laser at the WIS

At the Weizmann Institute of Science,a new high-power-laser laboratory has been established that is dedicated to the fundamental aspects of laser–matter interaction in the relativistic regime and aimed at developing compact laser-plasma accelerators for delivering high-brightness beams of electrons,ions,and x rays.The HIGGINS laser system delivers two independent 100 TW beams and an additional probe beam,and this paper describes its commissioning and presents the very first results for particle and radiation beam delivery.

Crossover from Two-to Three-dimensional Superconducting States in Bismuth-based Cuprate Superconductor

To decipher the mechanism of high temperature superconductivity(SC),it is important to know how the superconducting pairing emerges from the unusual normal states of cuprate superconductors,including pseudogap,anomalous Fermi liquid and strange metal(SM).A long-standing issue under debate is how the superconducting pairing is formed and condensed in the SM phase because the superconducting transition temperature is the highest in this phase.

Finding New Pairing Mechanism for Heavy Fermion Superconductivity

In heavy fermion superconductors,the effective mass of normal state heavy electrons can reach hundreds of times that of a free electron.Accordingly,the characteristic Fermi energy is reduced to the order of meV.Thus,the discovery of heavy fermion superconductivity in CeCu2Si2 by German scientist Frank Steglich in 1979 had two major consequences.First,the transition temperature(0.6 K)reaches 5%of the Fermi energy,much

20-qubit Schr?dinger Cat States with Superconducting Quantum Processor

A joint team of scientists,led by Prof.WANG Haohua from Zhejiang University and Profs.FAN Heng and ZHENG Dongning from the Institute of Physics,Chinese Academy of Sciences(CAS),successfully created Schrodinger cat states of up to20-qubits with a superconducting quantum processor.In addition,they demonstrated that the generated 18-qubit Greenberger-Horne-Zeilinger(GHZ)state is genuinely entangled.This marks the largest GHZ state ever created in solid state quantum computation platforms so far,and is thought to be a big step toward building a quantum computer.

Emmy Noether Looks at the Deconfined Quantum Critical Point

The deconfined quantum critical point (DQCP) describes a continuous phase transition between two phases that spontaneously breaks different symmetries [1]. Outside the realm of the Landau-Ginzburg-Wilson paradigm of phase transitions which is based on the concept of order parameter, the DQCP represents the new paradigm of quantum matter which manifests the concepts of fractionalized excitations (spinons in the model realization of the DQCP-the JQ model [2,3]) and emergent gauge structure and symmetry [4].

Synaptic Transistor Implemented Using Quasi-2D Molybdenum Oxide

Recent years has seen increasing interest in building artificial synaptic devices to emulate the computation performed by biological synapses.Biological synapses are functional links between neurons,through which information is transmitted in the neuron network.The information can be stored and processed simultaneously in the same synapse through tuning synaptic weight,which is defined as the strength of the correlation between

Excellent long-term reactivity of inhomogeneous nanoscale Fe-based metallic glass in wastewater purification

Metallic glasses(MGs)have attracted great attention in wastewater treatment because of their high reactivity arising from amorphous structure,large residual stress and high density of low coordination sites.However,the reactivity of MGs would gradually slow down with time due to the passivation of active sites by corrosion products,resulting in limited long-term reactivity,which is also an unsolved key issue for established crystalline zero valent iron(ZVI)technology.Here,such problems are successfully overcome by introducing nanoscale chemical inhomogeneities in Fe-based MG(Fe-MGI),which apparently contributes to local galvanic cell effect and accelerates electron transfer during degradation process.More importantly,the selective depletion of Fe0 causes local volume shrinkage and crack formation,leading to self-peeling of precipitated corrosion products and reacted regions.Thereby fresh low coordination sites could be continuously provided,counteracting the mass transport and reactivity deteriorating problem.Consequently,Fe-MGI demonstrates excellent long-term reactivity and self-refreshing properties even in neutral solution.The present results provide not only a new candidate but also a new route of designing ZVI materials for wastewater treatment.