Quantum

Paper

Fermion production at the boundary of an expanding universe: a cold-atom gravitational analogue

Carlos Fulgado-Claudio, Jose M. Sánchez Velázquez, and Alejandro Bermudez,

Quantum 7, 1042 (2023).

We study the phenomenon of cosmological particle production of Dirac fermions in a Friedmann-Robertson-Walker spacetime, focusing on a $(1+1)-$dimensional case in which the evolution of the sc…

Paper

Classification of measurement-based quantum wire in stabilizer PEPS

Paul Herringer and Robert Raussendorf,

Quantum 7, 1041 (2023).

We consider a class of translation-invariant 2D tensor network states with a stabilizer symmetry, which we call stabilizer PEPS. The cluster state, GHZ state, and states in the toric code be…

Paper

Avoiding symmetry roadblocks and minimizing the measurement overhead of adaptive variational quantum eigensolvers

V. O. Shkolnikov, Nicholas J. Mayhall, Sophia E. Economou, and Edwin Barnes,

Quantum 7, 1040 (2023).

Quantum simulation of strongly correlated systems is potentially the most feasible useful application of near-term quantum computers. Minimizing quantum computational resources is crucial to…

Paper

Deep recurrent networks predicting the gap evolution in adiabatic quantum computing

Naeimeh Mohseni, Carlos Navarrete-Benlloch, Tim Byrnes, and Florian Marquardt,

Quantum 7, 1039 (2023).

In adiabatic quantum computing finding the dependence of the gap of the Hamiltonian as a function of the parameter varied during the adiabatic sweep is crucial in order to optimize the speed…

Paper

On Quantum Steering and Wigner Negativity

Mattia Walschaers,

Quantum 7, 1038 (2023).

Quantum correlations and Wigner negativity are two important signatures of nonclassicality in continuous-variable quantum systems. In this work, we investigate how both are intertwined in th…

Paper

Generalized Belief Propagation Algorithms for Decoding of Surface Codes

Josias Old and Manuel Rispler,

Quantum 7, 1037 (2023).

Belief propagation (BP) is well-known as a low complexity decoding algorithm with a strong performance for important classes of quantum error correcting codes, e.g. notably for the quantum l…

Paper

Clifford Circuits can be Properly PAC Learned if and only if $\textsf{RP}=\textsf{NP}$

Daniel Liang,

Quantum 7, 1036 (2023).

Given a dataset of input states, measurements, and probabilities, is it possible to efficiently predict the measurement probabilities associated with a quantum circuit? Recent work of Caro a…

Paper

Unifying different notions of quantum incompatibility into a strict hierarchy of resource theories of communication

Francesco Buscemi, Kodai Kobayashi, Shintaro Minagawa, Paolo Perinotti, and Alessandro Tosini,

Quantum 7, 1035 (2023).

While there is general consensus on the definition of incompatible POVMs, moving up to the level of instruments one finds a much less clear situation, with mathematically different and logic…

Paper

Unifying and benchmarking state-of-the-art quantum error mitigation techniques

Daniel Bultrini, Max Hunter Gordon, Piotr Czarnik, Andrew Arrasmith, M. Cerezo, Patrick J. Coles, and Lukasz Cincio,

Quantum 7, 1034 (2023).

Error mitigation is an essential component of achieving a practical quantum advantage in the near term, and a number of different approaches have been proposed. In this work, we recognize th…

Paper

Measurement disturbance and conservation laws in quantum mechanics

M. Hamed Mohammady, Takayuki Miyadera, and Leon Loveridge,

Quantum 7, 1033 (2023).

Measurement error and disturbance, in the presence of conservation laws, are analysed in general operational terms. We provide novel quantitative bounds demonstrating necessary conditions un…

Paper

The $2T$-qutrit, a two-mode bosonic qutrit

Aurélie Denys and Anthony Leverrier,

Quantum 7, 1032 (2023).

Quantum computers often manipulate physical qubits encoded on two-level quantum systems. Bosonic qubit codes depart from this idea by encoding information in a well-chosen subspace of an inf…

Paper

On efficient quantum block encoding of pseudo-differential operators

Haoya Li, Hongkang Ni, and Lexing Ying,

Quantum 7, 1031 (2023).

Block encoding lies at the core of many existing quantum algorithms. Meanwhile, efficient and explicit block encodings of dense operators are commonly acknowledged as a challenging problem.…

Paper

On Quantum Speedups for Nonconvex Optimization via Quantum Tunneling Walks

Yizhou Liu, Weijie J. Su, and Tongyang Li,

Quantum 7, 1030 (2023).

Classical algorithms are often not effective for solving nonconvex optimization problems where local minima are separated by high barriers. In this paper, we explore possible quantum speedup…

Paper

Geometric phases along quantum trajectories

Ludmila Viotti, Ana Laura Gramajo, Paula I. Villar, Fernando C. Lombardo, and Rosario Fazio,

Quantum 7, 1029 (2023).

A monitored quantum system undergoing a cyclic evolution of the parameters governing its Hamiltonian accumulates a geometric phase that depends on the quantum trajectory followed by the syst…

Paper

Causal structure in the presence of sectorial constraints, with application to the quantum switch

Nick Ormrod, Augustin Vanrietvelde, and Jonathan Barrett,

Quantum 7, 1028 (2023).

Existing work on quantum causal structure assumes that one can perform arbitrary operations on the systems of interest. But this condition is often not met. Here, we extend the framework for…

Paper

Relaxation of Multitime Statistics in Quantum Systems

Neil Dowling, Pedro Figueroa-Romero, Felix A. Pollock, Philipp Strasberg, and Kavan Modi,

Quantum 7, 1027 (2023).

Equilibrium statistical mechanics provides powerful tools to understand physics at the macroscale. Yet, the question remains how this can be justified based on a microscopic quantum descript…

Category: Paper