Paper Clifford recompilation for faster classical simulation of quantum circuits Hammam Qassim, Joel J. Wallman, and Joseph Emerson, Quantum 3, 170 (2019). Simulating quantum circuits classically is an important area of research in quantum information, with applications in computational complexity and validation of quantum devices. One of the s…
Paper Simulating boson sampling in lossy architectures Raúl García-Patrón, Jelmer J. Renema, and Valery Shchesnovich, Quantum 3, 169 (2019). Photon losses are among the strongest imperfections affecting multi-photon interference. Despite their importance, little is known about their effect on boson sampling experiments. In this w…
Paper Tight, robust, and feasible quantum speed limits for open dynamics Francesco Campaioli, Felix A. Pollock, and Kavan Modi, Quantum 3, 168 (2019). Starting from a geometric perspective, we derive a quantum speed limit for arbitrary open quantum evolution, which could be Markovian or non-Markovian, providing a fundamental bound on the t…
Paper Applying quantum algorithms to constraint satisfaction problems Earl Campbell, Ankur Khurana, and Ashley Montanaro, Quantum 3, 167 (2019). Quantum algorithms can deliver asymptotic speedups over their classical counterparts. However, there are few cases where a substantial quantum speedup has been worked out in detail for reaso…
Paper Single-shot energetic-based estimator for entanglement in a half-parity measurement setup Cyril Elouard, Alexia Auffèves, and Géraldine Haack, Quantum 3, 166 (2019). Producing and certifying entanglement between distant qubits is a highly desirable skill for quantum information technologies. Here we propose a new strategy to monitor and characterize enta…
Paper Minimal energy cost of entanglement extraction Lucas Hackl and Robert H. Jonsson, Quantum 3, 165 (2019). We compute the minimal energy cost for extracting entanglement from the ground state of a bosonic or fermionic quadratic system. Specifically, we find the minimal energy increase in the syst…
Paper Nonadaptive fault-tolerant verification of quantum supremacy with noise Theodoros Kapourniotis and Animesh Datta, Quantum 3, 164 (2019). Quantum samplers are believed capable of sampling efficiently from distributions that are classically hard to sample from. We consider a sampler inspired by the classical Ising model. It is…
Paper Hamiltonian Simulation by Qubitization Guang Hao Low and Isaac L. Chuang, Quantum 3, 163 (2019). We present the problem of approximating the time-evolution operator $e^{-i\hat{H}t}$ to error $\epsilon$, where the Hamiltonian $\hat{H}=(\langle G|\otimes\hat{\mathcal{I}})\hat{U}(|G\rangle\otimes\hat{\mathcal{I}})$…
Paper Approximation Algorithms for Complex-Valued Ising Models on Bounded Degree Graphs Ryan L. Mann and Michael J. Bremner, Quantum 3, 162 (2019). We study the problem of approximating the Ising model partition function with complex parameters on bounded degree graphs. We establish a deterministic polynomial-time approximation scheme f…
Paper Fundamental limits on low-temperature quantum thermometry with finite resolution Patrick P. Potts, Jonatan Bohr Brask, and Nicolas Brunner, Quantum 3, 161 (2019). While the ability to measure low temperatures accurately in quantum systems is important in a wide range of experiments, the possibilities and the fundamental limits of quantum thermometry a…
Paper Quantizing time: Interacting clocks and systems Alexander R. H. Smith and Mehdi Ahmadi, Quantum 3, 160 (2019). This article generalizes the conditional probability interpretation of time in which time evolution is realized through entanglement between a clock and a system of interest. This formalism…
Paper Determining a local Hamiltonian from a single eigenstate Xiao-Liang Qi and Daniel Ranard, Quantum 3, 159 (2019). We ask whether the knowledge of a single eigenstate of a local Hamiltonian is sufficient to uniquely determine the Hamiltonian. We present evidence that the answer is “yes" for generic loca…
Paper Conjugates, Filters and Quantum Mechanics Alexander Wilce, Quantum 3, 158 (2019). The Jordan structure of finite-dimensional quantum theory is derived, in a conspicuously easy way, from a few simple postulates concerning abstract probabilistic models (each defined by a se…
Paper No-free-information principle in general probabilistic theories Teiko Heinosaari, Leevi Leppäjärvi, and Martin Plávala, Quantum 3, 157 (2019). In quantum theory, the no-information-without-disturbance and no-free-information theorems express that those observables that do not disturb the measurement of another observable and those…
Paper Variational Quantum Computation of Excited States Oscar Higgott, Daochen Wang, and Stephen Brierley, Quantum 3, 156 (2019). The calculation of excited state energies of electronic structure Hamiltonians has many important applications, such as the calculation of optical spectra and reaction rates. While low-depth…
Paper Quantized refrigerator for an atomic cloud Wolfgang Niedenzu, Igor Mazets, Gershon Kurizki, and Fred Jendrzejewski, Quantum 3, 155 (2019). We propose to implement a quantized thermal machine based on a mixture of two atomic species. One atomic species implements the working medium and the other implements two (cold and hot) bat…
