arXiv subjects

Eric Hudson

Publications and source records attributed to Eric Hudson.

6 recordsLinked to original sources

arXiv2026

Ab initio calculations of $^{229}$Th band-to-band internal conversion rate in $^{229}$ThO$_2$

We present an ab initio calculation of the band-to-band internal-conversion rate of the $\hbar\omega_{\rm nuc} \approx 8.35$ eV isomeric transition in $^{229}$ThO$_2$. Because the nuclear transition energy exceeds the electronic band gap of ThO$_2$, the isomer can decay nonradiatively by resonantly promoting a valence electron into the conduction band. We formulate this process as a Brillouin-zone sum over vertical interband transitions weighted by local Th-centered hyperfine matrix elements, which are evaluated directly from all-electron full-potential linearized augmented-plane-wave Bloch spinors. A finite nuclear magnetization model is included to regularize the short-range hyperfine interaction and to account for the Bohr-Weisskopf effect. After applying scissor shifts to span the experimentally reported ThO$_2$ band gaps, we find calculated internal-conversion lifetimes in the range of $1-16~\mu{\rm s}$. The lifetime increases strongly as the band gap approaches $\omega_{\rm nuc}$ because the resonant interband phase space at the nuclear transition energy is reduced. For the larger reported ThO$_2$ gaps, the calculated lifetime is comparable to the measured conversion-electron M\"ossbauer lifetime [Nature 648, 300 (2025)]. Our analysis implies that choosing solid-state hosts with band-gap values slightly lower than $\omega_{\rm nuc}$ can optimize solid-state nuclear clock performance with internal-conversion electron readout.

nucl-th↗

arXiv2025

Feasibility Study of 3D-Printed Micro Junction Array for Ion Trap Quantum Processor

We introduce an ion trap platform based on a 3D-printed micro-junction array, designed to implement quantum charge-coupled device (QCCD) architectures for large-scale quantum information processing (QIP). The integration of three-dimensionally structured micro Radio-Frequency (RF) electrodes above a surface-electrode trap enables flexible control of electric field profiles across both linear and junction regions. Through simulations, we demonstrate that the linear region exhibits deeper and more harmonic ion confinement with reduced RF drive power compared to conventional planar traps. Crucially, we identify a junction geometry that maintains uniform ion confinement during transport while substantially reducing the pseudopotential barrier. This reduction facilitates low-heating, high-fidelity transport of single- and multi-species ion crystals. Our results establish a viable route toward fault-tolerant quantum computing by enabling modular and scalable QCCD systems based on the state-of-the-art 3D-printing technologies.

quant-ph↗

arXiv2025

TrapSIMD: SIMD-Aware Compiler Optimization for 2D Trapped-Ion Quantum Machines

Modular trapped-ion (TI) architectures offer a scalable quantum computing (QC) platform, with native transport behaviors that closely resemble the Single Instruction Multiple Data (SIMD) paradigm. We present FluxTrap, a SIMD-aware compiler framework that establishes a hardware-software co-design interface for TI systems. FluxTrap introduces a novel abstraction that unifies SIMD-style instructions -- including segmented intra-trap shift SIMD (S3) and global junction transfer SIMD (JT-SIMD) operations -- with a SIMD-enriched architectural graph, capturing key features such as transport synchronization, gate-zone locality, and topological constraints. It applies two passes -- SIMD aggregation and scheduling -- to coordinate grouped ion transport and gate execution within architectural constraints. On NISQ benchmarks, FluxTrap reduces execution time by up to $3.82 \times$ and improves fidelity by several orders of magnitude. It also scales to fault-tolerant workloads under diverse hardware configurations, providing feedback for future TI hardware design.

quant-ph↗

arXiv2025

iSwitch: QEC on Demand via In-Situ Encoding of Bare Qubits for Ion Trap Architectures

Recent advances in quantum hardware and error correction have paved the way for early fault-tolerant (EFT) quantum computing. We propose iSwitch, a hybrid system architecture for trapped-ion quantum computers (TIQC) that exploits ultra-high-fidelity single-qubit gates and efficient logical CNOTs enabled by ion shuttling. iSwitch employs bare qubits for single-qubit operations and QEC-encoded logical qubits for two-qubit gates, avoiding full logical encoding, gate synthesis, and magic state distillation. To enable this selective encoding, we develop a low-noise conversion protocol between bare and logical qubits, a hybrid instruction set tailored to 2D TIQC layouts, and a compiler that minimizes conversion overhead and optimizes scheduling. Evaluations on variational quantum algorithm benchmarks show that iSwitch achieves comparable fidelity to conventional QEC methods, while reducing qubit and operation counts by roughly 33-50%, offering a practical, resource-efficient path toward EFT quantum computing on trapped-ion platforms.

quant-ph↗

arXiv2019

Nanoscale Thermal Imaging of VO$_2$ via Poole-Frenkel Conduction

We present a method for nanoscale thermal imaging of insulating thin films using atomic force microscopy (AFM), and we demonstrate its utility on VO$_2$. We sweep the applied voltage $V$ to a conducting AFM tip in contact mode and measure the local current $I$ through the film. By fitting the $IV$ curves to a Poole-Frenkel conduction model at low $V$, we calculate the local temperature with spatial resolution better than 50 nm using only fundamental constants and known film properties. Our thermometry technique enables local temperature measurement of \textit{any} insulating film dominated by the Poole-Frenkel conduction mechanism, and can be extended to insulators that display other conduction mechanisms.

cond-mat.str-el↗

arXiv2015

Using an ion trap with two temperature reservoirs to explore nonequilibrium physics

Using a combination of molecular dynamics simulations and fundamental statistical mechanics, we analyze the position and velocity distribution of a trapped ion immersed in two ideal gases at differing temperatures. Such a system has been realized in the recently developed MOTion trap architecture. This system has the potential to serve as platform for studying nonequilibrium statistical mechanics in a controlled environment. As examples, we demonstrate a non-Maxwell Boltzmann velocity ionic distribution in the trap, the breakdown of the fluctuation-dissipation theorem, and position-velocity sorting, wherein high-velocity ionic states are over represented at points of high potential energy. We propose experiments to test these predictions.

cond-mat.stat-mech↗