arXiv subjects

Jia-Qi Hu

Publications and source records attributed to Jia-Qi Hu.

5 recordsLinked to original sources

arXiv2026

Crosstalk-robust superconducting two-qubit geometric gates using tunable couplers

The design of coupler-based superconducting two-qubit gates simplifies circuit layout and alleviate frequency crowding, thereby enhancing the scalability and flexibility of quantum chips. However, in such architectures, a trade-off often exists between suppressing crosstalk and reducing gate duration, and how to achieve synergistic optimization of both remains an open challenge. To address this, this paper proposes a coupler-assisted superconducting two-qubit geometric gate scheme oriented towards crosstalk robustness. By introducing additional parametric degrees of freedom, the scheme steers the system evolution along desired trajectories, thereby flexibly avoiding crosstalk-sensitive operational regions. Numerical simulations demonstrate that the proposed scheme can effectively suppress crosstalk errors while enabling fast gate operations, and exhibits strong robustness against typical experimental imperfections such as qubit frequency drift. Moreover, even when accounting for unavoidable high-frequency oscillation terms and qubit decoherence in realistic physical systems, our crosstalk-robust two-qubit geometric gates still achieve high fidelity. This work provides a feasible pathway toward robust and efficient two-qubit gate implementation in superconducting quantum computation.

quant-ph↗

arXiv2026

Colloidal logic-gate circuits can process environmental signals and autonomously perform tasks

Cooperative collective dynamics is a principal determinant of the ability of synthetic micromotors to perform specific functions. However, realizing controllable and predictable collective behavior in complex physiological environments remains a significant challenge. Here, we show that collections of enzyme-coated colloids can be designed as various chemical logic gates, which subsequently can be organized into functional logic circuits. These circuits take environmental information as input signals and process it to produce output chemical species needed to achieve specific goals. The chemical computation performed by the circuit endows the active colloidal system with the ability to sense its surroundings and autonomously coordinate its collective motion. The results of simulations of several examples are presented, where self-assembled colloidal circuits can identify invasive threats by their signals, produce and deliver chemicals to the targets to suppress their activity. The results of this work can aid in the design of experimental chemical logic circuits through micromotor self-assembly that autonomously respond to environmental cues to execute specific tasks.

physics.chem-ph↗

arXiv2025

High-Order Modulation Large MIMO Detector Based on Physics-Inspired Methods

Applying quantum annealing or current quantum-/physics-inspired algorithms for MIMO detection always abandon the direct gray-coded bit-to-symbol mapping in order to obtain Ising form, leading to inconsistency errors. This often results in slow convergence rates and error floor, particularly with high-order modulations. We propose HOPbit, a novel MIMO detector designed to address this issue by transforming the MIMO detection problem into a higher-order unconstrained binary optimization (HUBO) problem while maintaining gray-coded bit-to-symbol mapping. The method then employs the simulated probabilistic bits (p-bits) algorithm to directly solve HUBO without degradation. This innovative strategy enables HOPbit to achieve rapid convergence and attain near-optimal maximum-likelihood performance in most scenarios, even those involving high-order modulations. The experiments show that HOPbit surpasses ParaMax by several orders of magnitude in terms of bit error rate (BER) in the context of 12-user massive and large MIMO systems even with computing resources. In addition, HOPbit achieves lower BER rates compared to other traditional detectors.

physics.comp-ph↗

arXiv2023

Universal Robust Geometric Quantum Control via Geometric Trajectory Correction

Universal robust quantum control is essential for performing complex quantum algorithms and efficient quantum error correction protocols. Geometric phase, as a key element with intrinsic fault-tolerant feature, can be well integrated into quantum control processes to enhance control robustness. However, the current geometric quantum control is still controversial in robust universality, which leads to the unsatisfactory result that cannot sufficiently enhance the robustness of arbitrary type of geometric gate. In this study, we find that the finite choice on geometric evolution trajectory is one of the main roots that constrain the control robustness of previous geometric schemes, as it is unable to optionally avoid some trajectory segments that are seriously affected by systematic errors. In view of this, we here propose a new scheme for universal robust geometric control based on geometric trajectory correction, where enough available evolution parameters are introduced to ensure that the effective correction against systematic errors can be executed. From the results of our numerical simulation, arbitrary type of geometric gate implemented by using the corrected geometric trajectory has absolute robustness advantages over conventional quantum one. In addition, we also verify the feasibility of the high-fidelity physical implementation of our scheme in superconducting quantum circuit, and finally discuss in detail the potential researches based on our scheme. Therefore, our theoretical work is expected to offer an attractive avenue for realizing practical fault-tolerant quantum computation in existing experimental platforms.

quant-ph↗

arXiv2023

Chemical logic gates on active colloids

Synthetic active colloidal systems are being studied extensively because of the diverse and often unusual phenomena these nonequilibrium systems manifest, and their potential applications in fields ranging from biology to material science. Recent studies have shown that active colloidal motors that use enzymatic reactions for propulsion hold special promise for applications that require motors to carry out active sensing tasks in complicated biomedical environments. In such applications it would be desirable to have active colloids with some capability of computation so that they could act autonomously to sense their surroundings and alter their own dynamics to perform specific tasks. Here we describe how small chemical networks that make use of enzymatic chemical reactions on the colloid surface can be used to construct motor-based chemical logic gates. Some basic features of coupled enzymatic reactions that are responsible for propulsion and underlie the construction and function of chemical gates are described using continuum theory and molecular simulation. Examples are given that show how colloids with specific chemical logic gates can perform simple sensing tasks. Due to the diverse functions of different enzyme gates, operating alone or in circuits, the work presented here supports the suggestion that synthetic motors using such gates could be designed to operate in an autonomous way in order to complete complicated tasks.

cond-mat.soft↗