Papers

We give a falsifiable protocol for demonstrating that a superconducting surface-code logical qubit remains below the fault-tolerance threshold at code distances larger than any distance publicly reported for that hardware modality at time of submission (the largest public result being d=7 with a 0.143% logical error rate per cycle and an inferred suppression factor Lambda ~ 2.14 per two-step increase in distance). Starting from the standard scaling ansatz for surface-code logical error rate, we derive the predicted suppression factor Lambda(d) = p_th/p per two-distance step, specify the statistical shot budget needed to resolve Lambda from unity at a stated confidence, and lay out exactly which raw per-shot syndrome data must be released -- not just aggregate logical error counts -- so any group can independently re-decode and audit the claim. We propose measuring distances d=9 and d=11 on the same qubit modality and give the concrete falsification criterion: a fitted log-error-rate-vs-distance slope inconsistent with monotonic below-threshold scaling, or a measured Lambda not statistically distinct across two independent steps, refutes the claim. No hardware experiment has been performed by the author; this is a theoretical and statistical protocol specifying what a genuine demonstration would require.

We investigate the black hole information paradox in the context of Jackiw-Teitelboim (JT) gravity coupled to a non-gravitational bath. Using the quantum extremal surface prescription, we show that the emergence of an island in the black hole interior after the Page time leads to a unitary Page curve for the entropy of Hawking radiation. The island contribution modifies the entropy of the radiation, causing it to decrease after the Page time and follow the expected Page curve. We compute the location of the quantum extremal surface explicitly in the eternal black hole setup and in the evaporating case, using the island formula. Our results demonstrate how semiclassical gravity can encode information recovery and resolve the paradox in a manageable two-dimensional model, providing insights into the quantum nature of black holes.

We propose an experimental scheme to measure Casimir forces in a non-equilibrium setting using ultracold atomic gases confined near a surface. By driving the gas out of equilibrium through laser-induced excitations, we predict significant enhancements and tunability of the Casimir force, arising from modified quantum fluctuations. Our calculations, based on a nonequilibrium Green's function approach, reveal novel spectral signatures and suggest that these forces can be probed with current ultracold atom technology, opening a pathway to study quantum thermodynamics and fluctuation-induced interactions in controlled out-of-equilibrium environments.

Ultralight scalar dark matter behaves as a coherent classical field oscillating at a frequency set by its mass, inducing a small periodic modulation of fundamental constants and hence of pulsar rotation. We derive, from the coupling of a scalar to the gluon field strength, the leading periodic signal imprinted on pulsar timing residuals, including its characteristic monochromatic frequency and its spatial correlation across a pulsar array. We show the signal is distinguishable from the stochastic gravitational-wave background by its narrow bandwidth and predict the amplitude as a function of the scalar coupling. We propose, but do not perform, a stacked-search analysis on existing public pulsar-timing-array data and give the sensitivity scaling. The prediction is falsifiable: a null result excludes a computable region of coupling-mass space.