Quantum

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…

Paper

Quantum computed moments correction to variational estimates

Harish J. Vallury, Michael A. Jones, Charles D. Hill, and Lloyd C. L. Hollenberg,

Quantum 4, 373 (2020).

The variational principle of quantum mechanics is the backbone of hybrid quantum computing for a range of applications. However, as the problem size grows, quantum logic errors and the effec…

Paper

Near-optimal ground state preparation

Lin Lin and Yu Tong,

Quantum 4, 372 (2020).

Preparing the ground state of a given Hamiltonian and estimating its ground energy are important but computationally hard tasks. However, given some additional information, these problems ca…

Paper

The Prime state and its quantum relatives

D. García-Martín, E. Ribas, S. Carrazza, J.I. Latorre, and G. Sierra,

Quantum 4, 371 (2020).

The Prime state of $n$ qubits, ${|\mathbb{P}_n{\rangle}}$, is defined as the uniform superposition of all the computational-basis states corresponding to prime numbers smaller than $2^n$. This sta…

Paper

Un-Weyl-ing the Clifford Hierarchy

Tefjol Pllaha, Narayanan Rengaswamy, Olav Tirkkonen, and Robert Calderbank,

Quantum 4, 370 (2020).

The teleportation model of quantum computation introduced by Gottesman and Chuang (1999) motivated the development of the Clifford hierarchy. Despite its intrinsic value for quantum computin…

Paper

Synthesis of CNOT-Dihedral circuits with optimal number of two qubit gates

Shelly Garion and Andrew W. Cross,

Quantum 4, 369 (2020).

In this note we present explicit canonical forms for all the elements in the two-qubit CNOT-Dihedral group, with minimal numbers of controlled-$S$ ($CS$) and controlled-$X$ ($CX$) gates, using the g…

Paper

A review of Quantum Cellular Automata

Terry Farrelly,

Quantum 4, 368 (2020).

Discretizing spacetime is often a natural step towards modelling physical systems. For quantum systems, if we also demand a strict bound on the speed of information propagation, we get quant…

Paper

Quantum reference frames for general symmetry groups

Anne-Catherine de la Hamette and Thomas D. Galley,

Quantum 4, 367 (2020).

A fully relational quantum theory necessarily requires an account of changes of quantum reference frames, where quantum reference frames are quantum systems relative to which other systems a…

Category: Paper