arXiv subjects

Edward Tortorici

Publications and source records attributed to Edward Tortorici.

3 recordsLinked to original sources

arXiv2026

Revealing Noise in Axial Motion Through Quantum Noise Spectroscopy on a Trapped Ion Processor

Native noise processes in quantum processors are often difficult to isolate because multiple error mechanisms contribute to the same measured loss of coherence. Here we use dephasing-robust quantum noise spectroscopy to identify and characterize control noise induced by axial motion in an individually-addressed trapped-ion processor. When the ion motion is transverse to the addressing beam, thermal axial motion couples to the beam profile and produces effective amplitude control noise. We show that this noise is governed primarily by the local beam curvature and appears as a low-frequency contribution to the reconstructed control-noise spectrum. By varying the ion position within the beam profile, we separate curvature-dependent axial-motion noise from curvature-independent native control noise and extract motional parameters that are otherwise difficult to access on this platform. We also apply the protocol in parallel to a four-ion register, demonstrating a spectroscopic method for simultaneous characterization of position-dependent control noise across multiple qubits. The results of this study identify beam inflection points as operating regions that suppress axial-motion-induced noise at the cost of reduced Rabi rate, as found in PRX Quantum 3, 010334 (2022).

quant-ph↗

arXiv2025

Grazing incidence X-ray scattering alignment using the area detector

Grazing incidence X-ray scattering experiments are designed to achieve strong scattering signals from materials, such as molecular monolayers, island films, or thin films that are localized to the surfaces of flat substrates. Optimal signals can be achieved with precise alignment of a substrate surface with the X-ray beam. Here, we outline a simple method that utilizes the area detector, generally available on such systems, to observe reflections from the sample to determine the sample-detector distance and the motor positions corresponding to the film being parallel to and centered in the beam. Observations of the reflected and transmitted beams are used to determine the critical angle of the sample and inform ideal motor angles that will lead to scattered X-ray intensity enhancement.

physics.ins-det↗

arXiv2016

A strong loophole-free test of local realism

We present a loophole-free violation of local realism using entangled photon pairs. We ensure that all relevant events in our Bell test are spacelike separated by placing the parties far enough apart and by using fast random number generators and high-speed polarization measurements. A high-quality polarization-entangled source of photons, combined with high-efficiency, low-noise, single-photon detectors, allows us to make measurements without requiring any fair-sampling assumptions. Using a hypothesis test, we compute p-values as small as $5.9\times 10^{-9}$ for our Bell violation while maintaining the spacelike separation of our events. We estimate the degree to which a local realistic system could predict our measurement choices. Accounting for this predictability, our smallest adjusted p-value is $2.3 \times 10^{-7}$. We therefore reject the hypothesis that local realism governs our experiment.

quant-ph↗