arXiv subjects

Bingzhao Li

Publications and source records attributed to Bingzhao Li.

8 recordsLinked to original sources

arXiv2026

Strategic Plan for Neutral Atom Quantum Computation

We present a strategic plan for neutral atom quantum computation, bringing together hardware development and theory advancements to achieve the goal of practical quantum advantage. The concept of practical quantum advantage is defined, along with how to verify claims of advantage, and approaches to designing quantum algorithms that deliver practical advantage. Future directions for neutral atom quantum processor hardware are described: scaling-up system size, Qubit encodings and atomic platforms, going further below threshold with neutral-atom logical-qubit performance, continuous reloading of qubits, and fast readout. We also explore opportunities for scalable integrated photonic control technologies. Alongside hardware advancements, new developments in quantum error correction and compilation of quantum circuits are proposed. Finally, we examine the opportunity of networking multiple neutral atom quantum processors together to perform distributed quantum computing and overcome possible limitations of a single system.

quant-ph↗

arXiv2026

Resonance-enhanced integrated acousto-optic beam steering

Optical beam steering is a key technology for free-space optical communication, sensing, and imaging. Mechanical beam steering systems suffer from limited scanning speed and bulky form factors, while existing solid-state solutions rely on pixelated synthetic aperture that requires complex fabrication and control architectures. Integrated acousto-optic beam steering (AOBS) is an emerging technology that enables continuous one-dimensional beam steering using integrated acoustic transducers and fixed-wavelength laser sources. Here, we integrate AOBS with an optical ring resonator on the same thin-film lithium niobate (TFLN) platform to significantly enhance beam steering efficiency and system functionality. The resulting device achieves a resonance-enhanced beam steering efficiency of up to $26\%$ and a field of view of $18^\circ$. Moreover, by leveraging integrated electro-optic control, we dynamically lock the ring-resonator's resonance to a chirped laser frequency, enabling frequency-modulated continuous-wave (FMCW) LiDAR operation. By combining lithium niobate's piezoelectric and electro-optic properties, this work establishes a compact, efficient, and scalable beam-steering platform with co-integrated acousto-optic modulation and electro-optic control for multifunctional applications.

physics.app-ph↗

arXiv2026

2D Optical Beam Scanning using Integrated Acousto-Optics and a Frequency Comb

Optical beam steering is an essential technology for free-space optical communication, reconfigurable optical networks and quantum information systems. Yet conventional steering methods either require bulky mechanical mechanisms, or rely on complex arrays of individually controlled light emitting elements. Integrated acousto-optic beam steering (AOBS) offers non-mechanical, continuous one-dimensional steering on-chip by using traveling acoustic waves with variable frequency to deflect light. In this work, we combine AOBS with an optical frequency comb and optical gratings to enable two-dimensional beam steering from a single aperture. Azimuthal scanning is controlled via acoustic frequency while polar coverage is realized by dispersing frequency comb lines with the gratings. We demonstrate this architecture by sequentially selecting and steering 11 comb lines spanning 1540-1570 nm, achieving a field of view of 18.2 by 4.3 degrees. Validation with a tunable laser extends polar coverage to 11.4 degrees. Both components are realized on the same thin-film lithium niobate platform, providing a pathway toward monolithic integration.

physics.optics↗

arXiv2026

Temperature-dependent acoustic loss at microwave frequencies in thin-film lithium niobate

Thin-film lithium niobate (TFLN) has emerged as a versatile platform for phononic and photonic devices with applications ranging from classical signal processing to quantum technologies. However, acoustic loss fundamentally limits the performance of acoustic devices on TFLN platforms, yet its physical origin remains insufficiently understood. Here, we systematically investigate acoustic propagation loss in various TFLN platforms, including lithium niobate on insulator (LNOI), lithium niobate on sapphire (LNOS), suspended LN thin films, and bulk LN at gigahertz frequencies over temperatures ranging from 4 K to above room temperature. Using a delay-line method, we extract frequency- and temperature-dependent losses for Rayleigh, shear-horizontal, and Lamb modes. We observe an anomalous non-monotonic temperature dependence in LNOI that closely resembles acoustic loss in amorphous materials, indicating a dominant loss channel associated with the buried oxide layer at low temperatures. At elevated temperatures, the loss converges to the Akhiezer damping governed by phonon-phonon interactions. High-resolution electron microscopy further reveals nanoscale interfacial crystal impurities that may contribute to the increased acoustic loss in TFLN platforms relative to bulk LN. These results elucidate the acoustic loss mechanisms in TFLN and provide guidelines for designing low-loss acoustic devices.

physics.app-ph↗

arXiv2024

Optical multi-beam steering and communication using integrated acousto-optics arrays

Optical beam steering enables optical detection and imaging in macroscopic or microscopic scales and long-range communication over free space. It underpins numerous optical applications, including LiDAR, biomedical imaging, and remote sensing. Despite the inherent speed of light, advanced applications increasingly require the ability to steer multiple beams simultaneously to increase imaging throughput, boost communication bandwidth, and control arrays qubits for scalable quantum computing. Therefore, there is a significant demand for non-mechanical, integrated, and scalable multi-beam steering technology. Here, we report a scalable multi-beam steering system comprising an array of acousto-optic beam steering channels and photonic integrated circuits on a thin-film lithium niobate platform. Each channel generates tens of individually controllable beams of visible wavelength by exciting acoustic waves using digitally synthesized multi-tone microwave signals. We demonstrate the system's capabilities through multi-input, multi-output free-space communications, simultaneously transmitting to multiple receivers at megabits/sec data rates. This technology can be readily scaled up to steer hundreds of optical beams from a compact chip, potentially advancing many areas of optical technologies and enabling novel applications.

physics.optics↗

arXiv2023

Optomechanical ring resonator for efficient microwave-optical frequency conversion

Phonons traveling in solid-state devices are emerging as a universal excitation that can couple to different physical systems through mechanical interaction. At microwave frequencies and in solid-state materials, phonons have a similar wavelength to optical photons, enabling them to interact efficiently with light and produce strong optomechanical effects that are highly desirable for classical and quantum signal transduction between optical and microwave. It becomes conceivable to build optomechanical integrated circuits (OMIC) that guide both photons and phonons and interconnect discrete photonic and phononic devices. Here, we demonstrate an OMIC including an optomechanical ring resonator (OMR), in which infrared photons and GHz phonons co-resonate to induce significantly enhanced interconversion. The OMIC is built on a hybrid platform where wide bandgap semiconductor gallium phosphide (GaP) is used as the waveguiding material and piezoelectric zinc oxide (ZnO) is used for phonon generation. The OMR features photonic and phononic quality factors of $>1\times10^5$ and $3.2\times10^3$, respectively, and resonantly enhances the optomechanical conversion between photonic modes to achieve an internal conversion efficiency $η_i=(2.1\pm0.1)%$ and a total device efficiency $η_{tot}=0.57\times10^{-6}$ at a low acoustic pump power of 1.6 mW. The efficient conversion in OMICs enables microwave-optical transduction for many applications in quantum information processing and microwave photonics.

physics.optics↗

arXiv2023

Silicon-lattice-matched boron-doped gallium phosphide: A scalable acousto-optic platform

The compact size, scalability, and strongly confined fields in integrated photonic devices enable new functionalities in photonic networking and information processing, both classical and quantum. Gallium phosphide (GaP) is a promising material for active integrated photonics due to its high refractive index, wide band gap, strong nonlinear properties, and large acousto-optic figure of merit. In this work we demonstrate that silicon-lattice-matched boron-doped GaP (BGaP), grown at the 12-inch wafer scale, provides similar functionalities as GaP. BGaP optical resonators exhibit intrinsic quality factors exceeding 25,000 and 200,000 at visible and telecom wavelengths respectively. We further demonstrate the electromechanical generation of low-loss acoustic waves and an integrated acousto-optic (AO) modulator. High-resolution spatial and compositional mapping, combined with ab initio calculations indicate two candidates for the excess optical loss in the visible band: the silicon-GaP interface and boron dimers. These results demonstrate the promise of the BGaP material platform for the development of scalable AO technologies at telecom and provide potential pathways toward higher performance at shorter wavelengths.

physics.optics↗

arXiv2021

Scaling optical computing in synthetic frequency dimension using integrated cavity acousto-optics

Optical computing with integrated photonics brings a pivotal paradigm shift to data-intensive computing technologies. However, the scaling of on-chip photonic architectures using spatially distributed schemes faces the challenge imposed by the fundamental limit of integration density. Synthetic dimensions of light offer the opportunity to extend the length of operand vectors within a single photonic component. Here, we show that large-scale, complex-valued matrix-vector multiplications on synthetic frequency lattices can be performed using an ultra-efficient, silicon-based nanophotonic cavity acousto-optic modulator. By harnessing the resonantly enhanced strong electro-optomechanical coupling, we achieve, in a single such modulator, the full-range phase-coherent frequency conversions across the entire synthetic lattice, which constitute a fully connected linear computing layer. Our demonstrations open up the route towards the experimental realizations of frequency-domain integrated optical computing systems simultaneously featuring very large-scale data processing and small device footprints.

physics.optics↗