arXiv subjects

Xiao-Jie Wang

Publications and source records attributed to Xiao-Jie Wang.

5 recordsLinked to original sources

arXiv2026

Storage of telecom-band time-bin qubits in thin-film lithium niobate

Integrated photonics has emerged as a promising platform for quantum communication and quantum computation. Thin-film lithium niobate (TFLN) has gained significant attention in this field due to its exceptional optical properties, enabling the realization of numerous integrated photonic devices. However, quantum memory, which serves as a universal building block for the quantum internet, has not yet been demonstrated in TFLN. In this study, we realized the first on-chip quantum memory using erbium ions doped TFLN. The developed quantum memory achieves a storage time of 400 ns with an efficiency of 1.95%, significantly outperforming conventional waveguide delay lines. The multimode capability is demonstrated by successfully storing four temporal modes. Furthermore, single-photon-level coherent pulses are encoded into time-bin qubits and stored with a fidelity of 96.8% , surpassing the classical limit achievable by measure-and-prepare strategy. Our results demonstrate the first on-chip quantum memory for telecom-band time-bin qubits in TFLN, providing a key building block toward integrated quantum registers and repeaters for scalable quantum information processing.

quant-ph↗

arXiv2025

Sub 10 nm Nanochannels Enable Directional Quasi Ballistic Exciton Transport over 5 μm at Room Temperature

Nanoscale potential wells provide a powerful means to engineer energy landscapes in low dimensional materials, enabling control over quantum states, carrier dynamics, and optoelectronic responses. Such confinement governs phenomena including charge localization, transport anisotropy, band structure modulation, and light matter interaction strength. However, realizing clean and well defined nanostructures remains technically challenging, as fabrication techniques such as focused ion beam (FIB) milling and electron beam lithography frequently introduce structural disorder, residual contamination, or detrimental interactions with the underlying substrate. Here, we develop a femtosecond laser direct writing technique to create sub 10 nm wide dielectric nanochannels with smooth, continuous boundaries on hexagonal boron nitride (hBN) substrates, without using resists or chemical etchants. As a demonstration, these nanochannels are employed to define programmable dielectric landscapes in monolayer molybdenum diselenide (MoSe2), forming excitonic energy funnels that suppress scattering and significantly extend the exciton transport distance. Transport is reshaped from isotropic diffusion with submicron range to directional super diffusion exhibiting quasi ballistic transport exceeding 5 um, more than 20 times longer than in unpatterned systems. The smooth dielectric boundaries further enable precise control over exciton trajectories, allowing for programmable transport pathways. This dry, scalable, and substrate compatible approach offers a robust platform for exciton engineering and integrated quantum photonic devices.

physics.optics↗

arXiv2025

Laser optothermal nanobomb for efficient flattening of nanobubbles in van der Waals materials

Nanobubbles are typical nanodefects commonly existing in two-dimensional (2D) van der Waals materials such as transition metal dioxides, especially after their transfer from growth substrate to target substrates. These nanobubbles, though tiny, may significantly alter the local electric, optoelectronic, thermal, or mechanical properties of 2D materials and therefore are rather detrimental to the constructed devices. However, there is no post-processing method so far that can effectively eliminate nanobubbles in 2D materials after their fabrication and transfer, which has been a major obstacle in the development of 2D material based devices. Here, we propose a principle, called laser optothermal nanobomb (LOTB), that can effectively flatten nanobubbles in 2D materials through a dynamic process of optothermally induced phase transition and stress-pulling effect in nanobubbles. Operation of LOTB on monolayer molybdenum disulfide (1L-MoS2) films shows that the surface roughness can be reduced by more than 70% on a time scale of ~50 ms, without damage to the intrinsic property of 1L-MoS2 as validated by micro-nano photoluminescence and Raman spectroscopy. Moreover, a dual-beam cascaded LOTB and a multi-shot LOTB strategies are proposed to increase the flattened area and processing effect, showing the potential of LOTB for fast nanodefect repairing in the mass production of van der Waals materials and devices.

physics.optics↗

arXiv2024

Super stealth dicing of transparent solids with nanometric precision

Laser cutting of semiconductor wafers and transparent dielectrics has become a dominant process in manufacturing industries, encompassing a wide range of applications from flat display panels to microelectronic chips. Limited by the diffraction barrier imposed on the beam width and its longitudinal extend of laser focus, a trade-off must be made between cutting accuracy and aspect ratio in conventional laser processing, with accuracy typically approaching a micron and the aspect ratio on the order of $10^2$. Herein, we propose a method to circumvent this limitation. It is based on the laser modification induced by a back-scattering interference crawling mechanism, which creates a positive feedback for homogenizing longitudinal energy deposition and lateral sub-wavelength light confinement during laser-matter interaction. Consequently, cutting width on the scale of tens of nanometers and aspect ratio $10^3 \sim 10^4$ were simultaneously achieved. We refer to this technique as ``super stealth dicing'', which is validated through numerical simulations, ensuring its broad applicability. It can be applied to various transparent functional solids, such as glass, laser crystal, ferroelectric, and semiconductor, and is elevating the precision of future advanced laser dicing, patterning, and drilling into the nanometric era.

physics.optics↗

arXiv2017

A way to measure the water quality of the LHAASO-WCDA with cosmic muon signals

The Large High Altitude Air Shower Observatory (LHAASO) is to be built at Daocheng, Sichuan Province, China. As one of the major components of the LHAASO project, a Water Cherenkov Detector Array (WCDA), with an area of 78,000~$\rm m^{2}$, contains 350,000~tons of purified water. The water transparency and its stability are critical for successful long-term operation of this project. To gain full knowledge of the water Cherenkov technique and investigate the engineering issues, a 9-cell detector array has been built at the Yangbajing site, Tibet, China. With the help of the distribution of single cosmic muon signals, the monitoring and measurement of water transparency are studied. The results show that a precision of several percent can be obtained for the attenuation length measurement, which satisfies the requirements of the experiment. In the near future, this method could be applied to the LHAASO-WCDA project.

physics.ins-det↗