Quantum

Paper

Separation of quantum, spatial quantum, and approximate quantum correlations

Salman Beigi,

Quantum 5, 389 (2021).

Quantum nonlocal correlations are generated by implementation of local quantum measurements on spatially separated quantum subsystems. Depending on the underlying mathematical model, various…

Paper

Overhead for simulating a non-local channel with local channels by quasiprobability sampling

Kosuke Mitarai and Keisuke Fujii,

Quantum 5, 388 (2021).

As the hardware technology for quantum computing advances, its possible applications are actively searched and developed. However, such applications still suffer from the noise on quantum de…

Paper

Defining quantum divergences via convex optimization

Hamza Fawzi and Omar Fawzi,

Quantum 5, 387 (2021).

We introduce a new quantum Rényi divergence $D^{\#}_{\alpha}$ for $\alpha \in (1,\infty)$ defined in terms of a convex optimization program. This divergence has several desirable computational a…

Paper

Measuring Analytic Gradients of General Quantum Evolution with the Stochastic Parameter Shift Rule

Leonardo Banchi and Gavin E. Crooks,

Quantum 5, 386 (2021).

Hybrid quantum-classical optimization algorithms represent one of the most promising application for near-term quantum computers. In these algorithms the goal is to optimize an observable qu…

Paper

Efficient quantum measurement of Pauli operators in the presence of finite sampling error

Ophelia Crawford, Barnaby van Straaten, Daochen Wang, Thomas Parks, Earl Campbell, and Stephen Brierley,

Quantum 5, 385 (2021).

Estimating the expectation value of an operator corresponding to an observable is a fundamental task in quantum computation. It is often impossible to obtain such estimates directly, as the…

Paper

The Multi-round Process Matrix

Timothée Hoffreumon and Ognyan Oreshkov,

Quantum 5, 384 (2021).

We develop an extension of the process matrix (PM) framework for correlations between quantum operations with no causal order that allows multiple rounds of information exchange for each par…

Paper

Measurement sequences for magic state distillation

Jeongwan Haah and Matthew B. Hastings,

Quantum 5, 383 (2021).

Magic state distillation uses special codes to suppress errors in input states, which are often tailored to a Clifford-twirled error model. We present detailed measurement sequences for magi…

Paper

How Dynamical Quantum Memories Forget

Lukasz Fidkowski, Jeongwan Haah, and Matthew B. Hastings,

Quantum 5, 382 (2021).

Motivated by recent work showing that a quantum error correcting code can be generated by hybrid dynamics of unitaries and measurements, we study the long time behavior of such systems. We d…

Paper

Autonomous Ticking Clocks from Axiomatic Principles

Mischa P. Woods,

Quantum 5, 381 (2021).

There are many different types of time keeping devices. We use the phrase $\textit{ticking clock}$ to describe those which – simply put – “tick'' at approximately regular intervals. Various i…

Paper

Exponentially faster implementations of Select(H) for fermionic Hamiltonians

Kianna Wan,

Quantum 5, 380 (2021).

We present a simple but general framework for constructing quantum circuits that implement the multiply-controlled unitary…

Paper

Experiment-friendly formulation of quantum backflow

Marek Miller, Woo Chee Yuan, Rainer Dumke, and Tomasz Paterek,

Quantum 5, 379 (2021).

Quantum backflow is usually understood as a quantum interference phenomenon where probability current of a quantum particle points in the opposite direction to particle's momentum. Here, we…

Paper

The three types of normal sequential effect algebras

Abraham Westerbaan, Bas Westerbaan, and John van de Wetering,

Quantum 4, 378 (2020).

A sequential effect algebra (SEA) is an effect algebra equipped with a $\textit{sequential product}$ operation modeled after the Lüders product $(a,b)\mapsto \sqrt{a}b\sqrt{a}$ on C$^*$-algebras.…

Paper

Multi-spin counter-diabatic driving in many-body quantum Otto refrigerators

Andreas Hartmann, Victor Mukherjee, Glen Bigan Mbeng, Wolfgang Niedenzu, and Wolfgang Lechner,

Quantum 4, 377 (2020).

Quantum refrigerators pump heat from a cold to a hot reservoir. In the few-particle regime, counter-diabatic (CD) driving of, originally adiabatic, work-exchange strokes is a promising candi…

Paper

High-Dimensional Pixel Entanglement: Efficient Generation and Certification

Natalia Herrera Valencia, Vatshal Srivastav, Matej Pivoluska, Marcus Huber, Nicolai Friis, Will McCutcheon, and Mehul Malik,

Quantum 4, 376 (2020).

Photons offer the potential to carry large amounts of information in their spectral, spatial, and polarisation degrees of freedom. While state-of-the-art classical communication systems rout…

Paper

Thermodynamics of Minimal Coupling Quantum Heat Engines

Marcin Łobejko, Paweł Mazurek, and Michał Horodecki,

Quantum 4, 375 (2020).

The minimal-coupling quantum heat engine is a thermal machine consisting of an explicit energy storage system, heat baths, and a working body, which alternatively couples to subsystems throu…

Paper

Translating Uncontrolled Systems in Time

David Trillo, Benjamin Dive, and Miguel Navascués,

Quantum 4, 374 (2020).

We show that there exist non-relativistic scattering experiments which, if successful, freeze out, speed up or even reverse the free dynamics of any ensemble of quantum systems present in th…

Category: Paper