Randomizing the readout time averages the mode interference in a quantum walk. We ask when this makes the site populations of a uniformly coupled $XY$ chain exactly uniform for every initial site. For $N\ge2$ spins, this is possible when $N+1$ is a power of two, a prime, or twice a prime. It is impossible when $15\mid(N+1)$, $21\mid(N+1)$, or $6\mid(N+1)$ with $N\ge11$. Uniformity uniquely fixes the averaged cosine coherences according to the mirror parities of the modes. Equal Bohr frequencies can impose incompatible coherence values. We classify these parity collisions using vanishing sums of roots of unity and prove existence in the positive cases through a phase distribution on a torus.
The quantum Zeno effect, in which frequent measurements suppress the evolution of a quantum system, is well characterized for static Hamiltonians. We investigate how periodic driving modifies Zeno protection for a single qubit on the superconducting processor ibm_marrakesh. In our gate‐based protocol, an interrupted Ra...
Prince N, Lalitha Nallamothula· Advanced Quantum Technologie...· 0 citations
Sampling-based quantum advantage raises a basic resource question: how much non-Gaussianity is needed to reproduce the random-matrix statistics often associated with quantum chaos? Passive fermionic linear optics preserves Gaussian structure, and even Haar-random mode mixing fails to anticoncentrate for Slater inputs....
Chen-Feng Cao, Yi-Fan Tang, J. Eisert· 0 citations
Random quantum circuits aim to efficiently reproduce the statistical properties of ideal random quantum evolution. One approach is to construct approximate unitary designs, which match the moments of Haar-random unitaries up to a prescribed order with controlled error. In this work, we establish quantitative guarantees...
We determine the time required for local weak measurements to collapse to one occupied site in an initial superposition of $N$ alternatives in the model of PRA 111, 032217 (2025). For equal initial occupation probabilities and a fixed confidence threshold $1-\delta$, we prove $T_N/\ln N\to1/2$ in $L^1$, with time measu...
Measures of non-stabilizerness (``magic'') of a quantum evolution quantify how hard it is to simulate on a classical computer. A natural question is how to extract information about magic from physical correlators, for example at finite temperature or in the ground state. In this paper we show how to measure magic usin...
Random unitary operations are a fundamental resource for quantum information processing, yet provably generating them with experimentally available controls remains challenging. Existing approaches often require calculating higher-order operator expectation values, relying on statistical assumptions about the experimen...
Oscar Scholin, Apollonas S. Matsoukas-Roubeas, Sathyawageeswar Subramanian· 0 citations
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