arXiv subjects

Y. Wei

Publications and source records attributed to Y. Wei.

At least 19 recordsLinked to original sources

arXiv2026

Accelerated Rydberg electromagnetically induced transparency quantum memory via shortcuts to adiabaticity

Electromagnetically induced transparency (EIT) enables coherent light-matter storage, forming the basis of photonic quantum memories that are essential for scalable quantum networks and distributed quantum computing. However, accelerating the storage process violates the adiabatic condition, resulting in the excitation of the lossy intermediate state and a reduction in writing efficiency. We propose and numerically investigate a high-speed, high-fidelity quantum storage scheme by incorporating a shortcut-to-adiabaticity (STA) technique based on counter-diabatic (CD) driving. By introducing a precisely engineered auxiliary field into a conventional EIT system, our protocol significantly shortens the writing time beyond the conventional adiabatic limit while effectively suppressing the transient population of the lossy intermediate state. Furthermore, our scheme demonstrates strong flexibility in pulse design, remaining effective across different temporal profiles of both the control and signal fields. It also exhibits robustness against imperfections in the CD drive. Even with imperfect single-photon writing and non-ideal Rydberg blockade, the scheme retains clear advantages, maintaining high storage performance and overcoming the intrinsic speed-fidelity trade-off of traditional EIT protocols. These features pave the way for fast and robust quantum devices suitable for high-throughput quantum repeaters and advanced quantum information processing.

quant-ph↗

arXiv2026

Timing and scintillation of a young Galactic halo pulsar

We present a timing and scintillation study of the young Galactic halo pulsar PSR J1740+1000 using observations from the Nanshan, FAST, and Parkes radio telescopes. From timing analysis, we measure the pulsar's proper motion for the first time, indicating motion away from the Galactic plane at a position angle of 16.7 +/- 4.8 degrees (Galactic coordinates), with a total proper motion of 56.9 +/- 8.0 mas/yr and a corresponding transverse velocity of 329 +/- 80 km/s. This velocity suggests that PSR J1740+1000 is a typical-velocity young pulsar born within the Galactic halo. In scintillation studies, we detect scintillation arcs, arclets, and double-layered adjacent arcs in the secondary spectra. Under isotropic and anisotropic scattering assumptions, the screen-to-pulsar distance is 370 +/- 72 pc and 1 +/- 12 pc, respectively. The latter closely matches the scale of the pulsar wind nebula associated with PSR J1740+1000 and provides a better fit, suggesting that scattering is likely dominated by the PWN. The double-layered adjacent arcs observed on MJD 60180 imply that the pulsar's scattered image consists of two dominant components (A and B) and multiple weaker components. Component A is located at the pulsar's geometric position (0 uas), while Component B is located 112 +/- 16 uas and 23 +/- 17 uas from the central component under isotropic and anisotropic scattering, respectively. The frequency-independent angular position of Component B hints at refraction by an AU-scale structure within the scattering region, possibly originating from the PWN.

astro-ph.GA↗

arXiv2025

Enhancing ground-state interaction strength of neutral atoms via Floquet stroboscopic dynamics

Neutral atom systems are promising platforms for quantum simulation and computation, owing to their long coherence times. However, their intrinsically weak ground-state interactions pose a major limitation to the advancement of scalable quantum simulation and computation. To address this challenge, we propose an approach to enhancing the ground-state interaction strength of neutral atoms via Floquet modulation of a Rydberg atomic ensemble. Each Floquet period consists of ground-state coupling followed by a pulse driving the transition from the ground state to the Rydberg state. Theoretical analysis and numerical simulations demonstrate that after a defined evolution time, neutral atoms within Rydberg ensembles can collectively form a $W$ state in the ground-state manifold. Even when the Rydberg interaction strength is far below the blockade regime, the fidelity remains remarkably high. Finally, we analyze the application of this scheme in the preparation of single-photon sources. In general, our proposed mechanism offers an efficient and highly controllable method for quantum state preparation within the Rydberg atomic ensembles, significantly enhancing the accuracy and stability of quantum state engineering while providing a well-controlled quantum environment for single-photon generation.

quant-ph↗

arXiv2025

Stepping into the Sea of Instability: The New Sub-us Superheavy Nucleus 252Rf

We report the discovery of the new isotope $^{252}$Rf. With its extremely short half-life of $60^{+90}_{-30}$~ns, it expands the range of half-lives of the known superheavy nuclei by about two orders of magnitude. This nucleus was synthesized in its high-$K$ isomeric state, for which we measured a half-life of $13^{+4}_{-3}$~$\mu$s. Our results confirm a smooth onset of decreasing ground-state spontaneous fission half-lives in the neutron-deficient Rf isotopes towards the isotopic border of $10^{-14}$~s, which is the time needed to form an atomic shell. Our findings set a new benchmark for further exploration of phenomena associated with high-$K$ states and inverted fission-stability in the heaviest nuclei.

nucl-ex↗

arXiv2022

Tensor Regularized Total Least Squares Methods with Applications to Image and Video Deblurring

Total least squares (TLS) is an effective method for solving linear equations with the situations, when noise is not just in observation matrices but also in mapping matrices. Moreover, the Tikhonov regularization is widely used in plenty of ill-posed problems. In this paper, we extend the regularized total least squares (RTLS) method from the matrix form due to Golub, Hansen and O'Leary, to the tensor form proposing the tensor regularized total least squares (TR-TLS) method for solving ill-conditioned tensor systems of equations. Properties and algorithms about the solution of the TR-TLS problem, which might be similar to those of the RTLS, are also presented and proved. Based on this method, some applications in image and video deblurring are explored. Numerical examples illustrate the TR-TLS, compared with the existing methods.

math.NA↗

arXiv2021

Hourly Warning for Strong Earthquakes

A promising perspective is presented that humans can provide hourly warning for strong land earthquakes (EQs, Ms6). Two important atmospheric electrostatic signal features are described. A table that lists 9 strong land EQs with shock time, epicenter, magnitude, weather in the region near the epicenter, precursor beginning time, and precursor duration demonstrates that at approximately several hours to one day before a strong land EQ, the weather conditions are fair near the epicenter, and an abnormal negative atmospheric electrostatic signal is very obvious. Moreover, the mechanism is explained. A method by which someone could determine the epicenter and the magnitude of a forthcoming strong EQ is suggested. Finally, the possibility of realizing hourly warning for strong land EQs in the near future is pointed out.

physics.geo-ph↗

arXiv2020

CMOS compatible high-performance nanolasing based on perovskite-SiN hybrid integration

Coherent light sources in silicon photonics are the long-sought holy grail because silicon-based materials have indirect bandgap. Traditional strategies for realizing such sources, e.g., heterogeneous photonic integration, strain engineering and nonlinear process, are technologically demanding. Here, we demonstrate a hybrid lasing device composing of perovskite nanocrystals and silicon nitride nanobeam cavity. We fabricate SiN photonic crystal naonobeam cavities on a solid substrate with significantly improved thermal and mechanical stabilities compared to conventional suspended ones. In addition, adding a PMMA-encapsulation layer on top of the SiN can significantly boost the Q-factor of the cavity mode. By dispersing perovskite nanocrystals as emitters in the PMMA layer, we obtained high-performance coherent emissions in terms of lasing threshold, linewidth and mode volumes. Our work offers a compelling way of creating solution-processed active integrated photonic devices based on the mature platform of silicon photonics for applications in optical information science and photonic quantum technology.

physics.optics↗

arXiv2020

LBECA: A Low Background Electron Counting Apparatus for Sub-GeV Dark Matter Detection

Two-phase noble liquid detectors, with large target masses and effective background reduction, are currently leading the dark matter direct detection for WIMP masses above a few GeV. Due to their sensitivity to single ionized electron signals, these detectors were shown to also have strong constraints for sub-GeV dark matter via their scattering on electrons. In fact, the most stringent direct detection constraints for sub-GeV dark matter down to as low as ~5 MeV come from noble liquid detectors, namely XENON10, DarkSide-50, XENON100 and XENON1T, although these experiments still suffer from high background at single or a few electron level. LBECA is a planned 100-kg scale liquid xenon detector with significant reduction of the single and a few electron background. The experiment will improve the sensitivity to sub-GeV dark matter by three orders of magnitude compared to the current best constraints.

physics.ins-det↗

arXiv2019

First test of a $\mathrm{CdMoO_4}$ scintillating bolometer for neutrinoless double beta decay experiments with $\mathrm{{}^{116}Cd}$ and $\mathrm{{}^{100}Mo}$ nuclides

A large cylindrical cadmium molybdate crystal with natural isotopic abundance has been used to fabricate a scintillating bolometer. The measurement was performed above ground at milli-Kelvin temperature, with simultaneous readout of the heat and the scintillation light. The energy resolution as FWHM has achieved from 5 keV (at 238 keV) to 13 keV (at 2615 keV). We present the results of the $α$ versus $β$/$γ$ events discrimination. The low internal trace contamination of the $\mathrm{CdMoO_4}$ crystal was evaluated as well. The detector performance with preliminary positive indications proves that cadmium molybdate crystal is a promising absorber for neutrinoless double beta decay scintillating bolometric experiments with $\mathrm{{}^{116}Cd}$ and $\mathrm{{}^{100}Mo}$ nuclides in the next-generation technique.

physics.ins-det↗

arXiv2019

Earth wind as a possible source of lunar surface hydration

Understanding the sources of lunar water is crucial for studying the history of lunar evolution, and also the solar wind interaction with the Moon and other airless bodies. Recent observations revealed lunar hydration is very likely a surficial dynamic process driven by solar wind. Solar wind is shielded over a period of 3-5 days as the Moon passes through the Earth's magnetosphere, during which a significant loss of hydration is expected from previous works.Here we study lunar hydration inside the magnetosphere using orbital spectral data, which unexpectedly found that the polar surficial OH/H2O abundance remains at the same level when in the solar wind and in the magnetosphere. We suggest that particles from the magnetosphere (Earth wind, naturally different from solar wind) contribute to lunar hydration. From lunar orbital plasma observations, we find the existence of optimal energy ranges, other than 1 keV as previously thought, for surface hydration formation. These optimal energy ranges deduced from space observations may provide strong implications for laboratory experiments simulating lunar hydration processes.

astro-ph.EP↗

arXiv2018

Designing plateaued Boolean functions in spectral domain and their classification

The design of plateaued functions over $GF(2)^n$, also known as 3-valued Walsh spectra functions (taking the values from the set $\{0, \pm 2^{\lceil \frac{n+s}{2} \rceil}\}$), has been commonly approached by specifying a suitable algebraic normal form which then induces this particular Walsh spectral characterization. In this article, we consider the reversed design method which specifies these functions in the spectral domain by specifying a suitable allocation of the nonzero spectral values and their signs. We analyze the properties of trivial and nontrivial plateaued functions (as affine inequivalent distinct subclasses), which are distinguished by their Walsh support $S_f$ (the subset of $GF(2)^n$ having the nonzero spectral values) in terms of whether it is an affine subspace or not. The former class exactly corresponds to partially bent functions and admits linear structures, whereas the latter class may contain functions without linear structures. A simple sufficient condition on $S_f$, which ensures the nonexistence of linear structures, is derived and some generic design methods of nontrivial plateaued functions without linear structures are given. The extended affine equivalence of plateaued functions is also addressed using the concept of dual of plateaued functions. Furthermore, we solve the problem of specifying disjoint spectra (non)trivial plateaued functions of maximal cardinality whose concatenation can be used to construct bent functions in a generic manner. This approach may lead to new classes of bent functions due to large variety of possibilities to select underlying duals that define these disjoint spectra plateaued functions. An additional method of specifying affine inequivalent plateaued functions, obtained by applying a nonlinear transform to their input domain, is also given.

cs.IT↗

arXiv2018

A general framework for secondary constructions of bent and plateaued functions

In this work, we employ the concept of {\em composite representation} of Boolean functions, which represents an arbitrary Boolean function as a composition of one Boolean function and one vectorial function, for the purpose of specifying new secondary constructions of bent/plateaued functions. This representation gives a better understanding of the existing secondary constructions and it also allows us to provide a general construction framework of these objects. This framework essentially gives rise to an {\em infinite number} of possibilities to specify such secondary construction methods (with some induced sufficient conditions imposed on initial functions) and in particular we solve several open problems in this context. We provide several explicit methods for specifying new classes of bent/plateaued functions and demonstrate through examples that the imposed initial conditions can be easily satisfied. Our approach is especially efficient when defining new bent/plateaued functions on larger variable spaces than initial functions. For instance, it is shown that the indirect sum methods and Rothaus' construction are just special cases of this general framework and some explicit extensions of these methods are given. In particular, similarly to the basic indirect sum method of Carlet, we show that it is possible to derive (many) secondary constructions of bent functions without any additional condition on initial functions apart from the requirement that these are bent functions. In another direction, a few construction methods that generalize the secondary constructions which do not extend the variable space of the employed initial functions are also proposed.

cs.IT↗

arXiv2018

Study of ultra-high gradient acceleration in carbon nanotube arrays

Solid-state based wakefield acceleration of charged particles was previously proposed to obtain extremely high gradients on the order of 1-10 TeV/m. In recent years the possibility of using either metallic or carbon nanotube structures is attracting new attention. The use of carbon nanotubes would allow us to accelerate and channel particles overcoming many of the limitations of using natural crystals, e.g. channeling aperture restrictions and thermal-mechanical robustness issues. In this paper, we propose a potential proof of concept experiment using carbon nanotube arrays, assuming the beam parameters and conditions of accelerator facilities already available, such as CLEAR at CERN and CLARA at Daresbury. The acceleration performance of carbon nanotube arrays is investigated by using a 2D Particle-In-Cell (PIC) model based on a multi-hollow plasma. Optimum experimental beam parameters and system layout are discussed.

physics.acc-ph↗

arXiv2017

Overdense microwave plasma heating in the CNT stellarator

Overdense plasmas have been attained with 2.45 GHz microwave heating in the low-field, low-aspect-ratio CNT stellarator. Densities higher than four times the ordinary (O) mode cutoff density were measured with 8 kW of power injected in the O-mode and, alternatively, with 6.5 kW in the extraordinary (X) mode. The temperature profiles peak at the plasma edge. This was ascribed to collisional damping of the X-mode at the upper hybrid resonant layer. The X-mode reaches that location by tunneling, mode-conversions or after polarization-scrambling reflections off the wall and in-vessel coils, regardless of the initial launch being in O- or X-mode. This interpretation was confirmed by full-wave numerical simulations. Also, as the CNT plasma is not completely ionized at these low microwave power levels, electron density was shown to increase with power. A dependence on magnetic field strength was also observed (for O-mode launch) and discussed.

physics.plasm-ph↗

arXiv2017

Qualification Tests of the R11410-21 Photomultiplier Tubes for the XENON1T Detector

The Hamamatsu R11410-21 photomultiplier tube is the photodetector of choice for the XENON1T dual-phase time projection chamber. The device has been optimized for a very low intrinsic radioactivity, a high quantum efficiency and a high sensitivity to single photon detection. A total of 248 tubes are currently operated in XENON1T, selected out of 321 tested units. In this article the procedures implemented to evaluate the large number of tubes prior to their installation in XENON1T are described. The parameter distributions for all tested tubes are shown, with an emphasis on those selected for XENON1T, of which the impact on the detector performance is discussed. All photomultipliers have been tested in a nitrogen atmosphere at cryogenic temperatures, with a subset of the tubes being tested in gaseous and liquid xenon, simulating their operating conditions in the dark matter detector. The performance and evaluation of the tubes in the different environments is reported and the criteria for rejection of PMTs are outlined and quantified.

astro-ph.IM↗

arXiv2016

Optimizing the placement of tap positions and guess and determine cryptanalysis with variable sampling

In this article an optimal selection of tap positions for certain LFSR-based encryption schemes is investigated from both design and cryptanalytic perspective. Two novel algorithms towards an optimal selection of tap positions are given which can be satisfactorily used to provide (sub)optimal resistance to some generic cryptanalytic techniques applicable to these schemes. It is demonstrated that certain real-life ciphers (e.g. SOBER-t32, SFINKS and Grain-128), employing some standard criteria for tap selection such as the concept of full difference set, are not fully optimized with respect to these attacks. These standard design criteria are quite insufficient and the proposed algorithms appear to be the only generic method for the purpose of (sub)optimal selection of tap positions. We also extend the framework of a generic cryptanalytic method called Generalized Filter State Guessing Attacks (GFSGA), introduced in [26] as a generalization of the FSGA method, by applying a variable sampling of the keystream bits in order to retrieve as much information about the secret state bits as possible. Two different modes that use a variable sampling of keystream blocks are presented and it is shown that in many cases these modes may outperform the standard GFSGA mode. We also demonstrate the possibility of employing GFSGA-like attacks to other design strategies such as NFSR-based ciphers (Grain family for instance) and filter generators outputting a single bit each time the cipher is clocked. In particular, when the latter scenario is considered, the idea of combining GFSGA technique and algebraic attacks appears to be a promising unified cryptanalytic method against NFSR-based stream ciphers.

cs.IT↗

arXiv2016

Onion-peeling inversion of stellarator images

An onion-peeling technique is developed for inferring the emissivity profile of a stellarator plasma from a two-dimensional image acquired through a CCD or CMOS camera. Each pixel in the image is treated as an integral of emission along a particular line-of-sight. Additionally, the flux surfaces in the plasma are partitioned into discrete layers, each of which is assumed to have uniform emissivity. If the topology of the flux surfaces is known, this construction permits the development of a system of linear equations that can be solved for the emissivity of each layer. We present initial results of this method applied to wide-angle visible images of the CNT stellarator plasma.

physics.plasm-ph↗

arXiv2015

AWAKE, The Advanced Proton Driven Plasma Wakefield Acceleration Experiment at CERN

The Advanced Proton Driven Plasma Wakefield Acceleration Experiment (AWAKE) aims at studying plasma wakefield generation and electron acceleration driven by proton bunches. It is a proof-of-principle R&D experiment at CERN and the world's first proton driven plasma wakefield acceleration experiment. The AWAKE experiment will be installed in the former CNGS facility and uses the 400 GeV/c proton beam bunches from the SPS. The first experiments will focus on the self-modulation instability of the long (rms ~12 cm) proton bunch in the plasma. These experiments are planned for the end of 2016. Later, in 2017/2018, low energy (~15 MeV) electrons will be externally injected to sample the wakefields and be accelerated beyond 1 GeV. The main goals of the experiment will be summarized. A summary of the AWAKE design and construction status will be presented.

physics.acc-ph↗