arXiv subjects

Sanghyo Park

Publications and source records attributed to Sanghyo Park.

3 recordsLinked to original sources

arXiv2026

Sensitivity threshold defines the optimal spin subset for ensemble quantum sensing

Inhomogeneous broadening and spatial gradients in control fields inevitably produce large variations in characteristic sensitivity across spin ensembles. We derive an analytic expression for the sensitivity of an inhomogeneous ensemble and introduce a sensitivity threshold that identifies the optimal subset of spins. For both pulsed and continuous-wave magnetometry, the optimal ensembles deliver up to an eightfold improvement over conventional schemes relying on nominally uniform regions of the ensemble. We demonstrate phase-only digital holography to implement the optimal ensembles and show that the measured illumination non-uniformity limits the sensitivity by 14%. This approach enables optimal quantum sensing in optically scattering environments.

quant-ph↗

arXiv2025

Autonomously Designed Pulses for Precise, Site-Selective Control of Atomic Qubits

Quantum computers based on cold-atom arrays offer long-lived qubits with programmable connectivity, yet their progress toward fault-tolerant operation is limited by the relatively low fidelity of site-selective local control. We introduce an artificial-intelligence (AI) framework that overcomes this limitation. Trained on atom-laser dynamics, a deep neural network autonomously designs composite pulses that improve local control fidelities tenfold while remaining compatible with existing control hardware. We further demonstrate the robustness of these pulses against optical aberrations and beam misalignment. This approach establishes AI-trained pulse compilation for high-fidelity qubit control and can be readily extended to other atom-like platforms, such as trapped ions and solid-state color centers.

quant-ph↗

arXiv2024

Technologies for Modulation of Visible Light and their Applications

Control over the amplitude, phase, and spatial distribution of visible-spectrum light underlies many technologies, but commercial solutions remain bulky, require high control power, and are often too slow. Active integrated photonics for visible light promises a solution, especially with recent materials and fabrication advances. In this review, we discuss three growing application spaces which rely on control of visible light: control and measurement of atomic quantum technologies, augmented-reality displays, and measurement and control of biological systems. We then review the commercial dynamic surfaces and bulk systems which currently provide visible-light modulation and the current state-of-the-art integrated solutions. Throughout the review we focus on speed, control power, size, optical bandwidth, and technological maturity when comparing technologies.

physics.optics↗