Quantum Physics
Gate-based digital quantum simulations offer an exciting new paradigm for studying the many-body physics of strongly correlated systems. In this context, electron-phonon models are challenging for qubit-only quantum simulators, as bosonic…
The multi-qubit gates fidelity of superconducting quantum processors can be limited due to the dressing of computational states by noncomputational ones. Here, we experimentally and analytically investigate a transmon-transmon-bus system…
Deterministic sources of entangled photon pairs and indistinguishable photons are expected to play a key role in photonic quantum technologies. Semiconductor quantum dots are promising candidates due to their on-demand emission and…
Neutral Atom Quantum Computing (NAQC) is an emerging modality for scalable quantum computation, valued for its long coherence times and the naturally identical atomic qubits. However, one of the main drawbacks is its slow execution rate,…
We investigate discrete dynamics in quantum circuits with gates corresponding to the S-matrix of a supersymmetric 1+1D quantum field theory. We show that for a brick-wall configuration such circuits support both localized and delocalized…
We investigate the non-Hermitian skin effect (NHSE) and topological phases in a ladder model with staggered nonreciprocal inter-leg hopping, consisting of an Su-Schrieffer-Heeger (SSH) chain coupled to a normal tight-binding chain. By…
Second-order boundary value problems are central to computational science, yet standard matrix-based numerical formulations can obscure the local geometric structure that quantum circuits may exploit. Here we introduce a framework for…
Quantum oracles are a common building block of many quantum algorithms, where circuit depth is a primary cost that directly affects overall performance. Synthesizing oracles for SAT (CNF) formulas under a limited ancilla budget, however,…
Testing quantum states for symmetries has multiple applications in quantum state comparison or as a primitive in more complex quantum algorithms. We present a method that determines whether an input photonic state is invariant under the…
We investigate the use of variational quantum algorithms to prepare and characterize fractional quantum Hall states on near-term quantum processors. Focusing on the $\nu=1/3$ Laughlin phase described by the $V_1$ Haldane pseudopotential, we…
Moment-based relaxations of the positive partial transpose (PPT) criterion have been recently introduced, as a hierarchy of entanglement criteria involving only experimentally accessible quantities of a given bipartite state. The goal of…
We control the spectral distribution of a spin ensemble by applying a magnetic field gradient using an anti-Helmholtz coil inside a dilution refrigerator, and demonstrate impedance matching between the ensemble and a transmission line,…
Privacy of a quantum metrological protocol concerns the extent to which single parameters can be kept inaccessible to an observer or to other users of the network. In this work, an information geometric framework is developed to quantify…
Weak values (WVs) arise from weak measurements performed within a time-symmetric formulation of quantum mechanics, where a system is both pre- and post-selected. Anomalous WVs that lie far outside the eigenvalue spectrum of the observable…
The short Doppler-limited coherence time of the laser-excited Rydberg state, usually orders of magnitude shorter than the lifetime of the Rydberg state, hinders the Rydberg-mediated quantum technologies. Here, we show that a…
Quantum state tomography is sample-starved, and the states one prepares live on a narrow, learnable manifold. A $k{=}0$ prior-only control shows that on concentrated families a prior estimate is already near-optimal, so ``high fidelity at…
We demonstrate the feasibility of entanglement-based quantum key distribution (eQKD) in high-security financial infrastructure over a 22 km fiber link with 8 dB loss between two data centers using polarization entanglement. The fully…
Distributed quantum computation needs to move logical qubits across lossy optical links, yet this transmission layer is usually designed separately from the computation it serves. We treat the two together by recognizing that a…
Finite quantum-logical constructions can appear classical or nonclassical depending on which structure is retained. We distinguish incidence tests based on valuations, colorings, and partition representations; simplex-embedding tests for…
Multiscale modeling of complex chemical systems requires algorithms that operate coherently across electronic, atomistic, mesoscopic, and continuum scales. While quantum algorithms have been proposed for each regime, no systematic framework…