Quantum

Paper

The advantage of quantum control in many-body Hamiltonian learning

Alicja Dutkiewicz, Thomas E. O’Brien, and Thomas Schuster,

Quantum 8, 1537 (2024).

We study the problem of learning the Hamiltonian of a many-body quantum system from experimental data. We show that the rate of learning depends on the amount of control available during the…

Paper

Separating a particle’s mass from its momentum

Mordecai Waegell, Jeff Tollaksen, and Yakir Aharonov,

Quantum 8, 1536 (2024).

The Quantum Cheshire Cat experiment showed that when weak measurements are performed on pre- and post-selected system, the counterintuitive result has been obtained that a neutron is measure…

Paper

LX-mixers for QAOA: Optimal mixers restricted to subspaces and the stabilizer formalism

Franz G. Fuchs and Ruben Pariente Bassa,

Quantum 8, 1535 (2024).

We present a novel formalism to both understand and construct mixers that preserve a given subspace. The method connects and utilizes the stabilizer formalism that is used in error correctin…

Paper

Time dependent Markovian master equation beyond the adiabatic limit

Giovanni Di Meglio, Martin B. Plenio, and Susana F. Huelga,

Quantum 8, 1534 (2024).

We derive a Markovian master equation that models the evolution of systems subject to driving and control fields. Our approach combines time rescaling and weak-coupling limits for the system…

Paper

Flying Spin Qubits in Quantum Dot Arrays Driven by Spin-Orbit Interaction

D. Fernández-Fernández, Yue Ban, and G. Platero,

Quantum 8, 1533 (2024).

Quantum information transfer is fundamental for scalable quantum computing in any potential platform and architecture. Hole spin qubits, owing to their intrinsic spin-orbit interaction (SOI)…

Paper

Grover Speedup from Many Forms of the Zeno Effect

Jesse Berwald, Nicholas Chancellor, and Raouf Dridi,

Quantum 8, 1532 (2024).

It has previously been established that adiabatic quantum computation, operating based on a continuous Zeno effect due to dynamical phases between eigenstates, is able to realise an optimal…

Paper

On proving the robustness of algorithms for early fault-tolerant quantum computers

Rutuja Kshirsagar, Amara Katabarwa, and Peter D. Johnson,

Quantum 8, 1531 (2024).

The hope of the quantum computing field is that quantum architectures are able to scale up and realize fault-tolerant quantum computing. Due to engineering challenges, such “cheap'' error c…

Paper

Constant-depth circuits for Boolean functions and quantum memory devices using multi-qubit gates

Jonathan Allcock, Jinge Bao, Joao F. Doriguello, Alessandro Luongo, and Miklos Santha,

Quantum 8, 1530 (2024).

We explore the power of the unbounded Fan-Out gate and the Global Tunable gates generated by Ising-type Hamiltonians in constructing constant-depth quantum circuits, with particular attentio…

Paper

Inevitability of knowing less than nothing

Gilad Gour, Mark M. Wilde, S. Brandsen, and Isabelle Jianing Geng,

Quantum 8, 1529 (2024).

A colloquial interpretation of entropy is that it is the knowledge gained upon learning the outcome of a random experiment. Conditional entropy is then interpreted as the knowledge gained up…

Paper

Construction of perfect tensors using biunimodular vectors

Suhail Ahmad Rather,

Quantum 8, 1528 (2024).

Dual unitary gates are highly non-local two-qudit unitary gates that have been studied extensively in quantum many-body physics and quantum information in the recent past. A special class of…

Paper

Combinatorial NLTS From the Overlap Gap Property

Eric R. Anschuetz, David Gamarnik, and Bobak Kiani,

Quantum 8, 1527 (2024).

In an important recent development, Anshu, Breuckmann, and Nirkhe [3] resolved positively the so-called No Low-Energy Trivial State (NLTS) conjecture by Freedman and Hastings. The conjecture…

Paper

Grothendieck inequalities characterize converses to the polynomial method

Jop Briët, Francisco Escudero Gutiérrez, and Sander Gribling,

Quantum 8, 1526 (2024).

A surprising 'converse to the polynomial method' of Aaronson et al. (CCC'16) shows that any bounded quadratic polynomial can be computed exactly in expectation by a 1-query algorithm up to a…

Paper

Ground and Excited States from Ensemble Variational Principles

Lexin Ding, Cheng-Lin Hong, and Christian Schilling,

Quantum 8, 1525 (2024).

The extension of the Rayleigh-Ritz variational principle to ensemble states $\rho_{\mathbf{w}}\equiv\sum_k w_k |\Psi_k\rangle \langle\Psi_k|$ with fixed weights $w_k$ lies ultimately at the hear…

Paper

Observational entropy with general quantum priors

Ge Bai, Dominik Šafránek, Joseph Schindler, Francesco Buscemi, and Valerio Scarani,

Quantum 8, 1524 (2024).

Observational entropy captures both the intrinsic uncertainty of a thermodynamic state and the lack of knowledge due to coarse-graining. We demonstrate two interpretations of observational e…

Paper

Gradients and frequency profiles of quantum re-uploading models

Alice Barthe and Adrián Pérez-Salinas,

Quantum 8, 1523 (2024).

Quantum re-uploading models have been extensively investigated as a form of machine learning within the context of variational quantum algorithms. Their trainability and expressivity are not…

Paper

Anomalous Floquet Phases. A resonance phenomena

Álvaro Gómez-León,

Quantum 8, 1522 (2024).

Floquet topological phases emerge when systems are periodically driven out-of-equilibrium. They gained attention due to their external control, which allows to simulate a wide variety of sta…

Category: Paper