# All

## Experimental Engineering of Arbitrary Qudit States with Discrete-Time Quantum Walks

Author(s): Taira Giordani, Emanuele Polino, Sabrina Emiliani, Alessia Suprano, Luca Innocenti, Helena Majury, Lorenzo Marrucci, Mauro Paternostro, Alessandro Ferraro, Nicolò Spagnolo, and Fabio Sciarrino
The capability to generate and manipulate quantum states in high-dimensional Hilbert spaces is a crucial step for the development of quantum technologies, from quantum communication to quantum computation. One-dimensional quantum walk dynamics represents a valid tool in the task of engineering arbit...

## Learning a Local Hamiltonian from Local Measurements

Author(s): Eyal Bairey, Itai Arad, and Netanel H. Lindner
Recovering an unknown Hamiltonian from measurements is an increasingly important task for certification of noisy quantum devices and simulators. Recent works have succeeded in recovering the Hamiltonian of an isolated quantum system with local interactions from long-ranged correlators of a single ei...
[Phys. Rev. Lett. 122, 020504] Published Fri Jan 18, 2019

## Passive, deterministic photonic conditional-<span class="sc">phase</span> gate via two-level systems

Author(s): William Konyk and Julio Gea-Banacloche
We show that an array of identical two-level systems coupled losslessly to a one-dimensional waveguide is able to realize a high-fidelity conditional phase shift useful for quantum logic. We propose two arrangements of emitters (one that relies on direct interactions between the emitters, and one th...
[Phys. Rev. A 99, 010301(R)] Published Fri Jan 18, 2019

## Scattering quantum random walks on square grids and randomly generated mazes

Author(s): Daniel Koch
The scattering-quantum-random-walk scheme has found success as a basis for search algorithms on highly symmetric graph structures. In this paper we examine its effectiveness at locating a specially marked vertex on square grid graphs, consisting of ${N}^{2}$ nodes. We simulate these quantum systems ...
[Phys. Rev. A 99, 012330] Published Fri Jan 18, 2019

## Realizing quantum linear regression with auxiliary qumodes

Author(s): Dan-Bo Zhang, Zheng-Yuan Xue, Shi-Liang Zhu, and Z. D. Wang
In order to exploit quantum advantages, quantum algorithms are indispensable for operating machine learning with quantum computers. We here propose an intriguing hybrid approach of quantum information processing for quantum linear regression, which utilizes both discrete and continuous quantum varia...
[Phys. Rev. A 99, 012331] Published Fri Jan 18, 2019

## Symmetric versus bosonic extension for bipartite states

Author(s): Youning Li, Shilin Huang, Dong Ruan, and Bei Zeng
A bipartite state ${ρ}^{AB}$ has a $k$-symmetric extension if there exists a ($k+1$)-partite state ${ρ}^{A{B}_{1}{B}_{2}...{B}_{k}}$ with marginals ${ρ}^{A{B}_{i}}={ρ}^{AB},∀i$. The $k$-symmetric extension is called bosonic if ${ρ}^{A{B}_{1}{B}_{2}...{B}_{k}}$ is supported on the symmetric subspace ...
[Phys. Rev. A 99, 012332] Published Fri Jan 18, 2019

## Floquet engineering in superconducting circuits: From arbitrary spin-spin interactions to the Kitaev honeycomb model

Author(s): Mahdi Sameti and Michael J. Hartmann
We derive a theory for the generation of arbitrary spin-spin interactions in superconducting circuits via periodic time modulation of the individual qubits or the qubit-qubit interactions. The modulation frequencies in our approach are in the microwave or radio-frequency regime, so the required fiel...
[Phys. Rev. A 99, 012333] Published Fri Jan 18, 2019

## Mitigating algorithmic errors in a Hamiltonian simulation

Author(s): Suguru Endo, Qi Zhao, Ying Li, Simon Benjamin, and Xiao Yuan
Quantum computers can efficiently simulate many-body systems. As a widely used Hamiltonian simulation tool, the Trotter-Suzuki scheme splits the evolution into the number of Trotter steps $N$ and approximates the evolution of each step by a product of exponentials of each individual term of the tota...
[Phys. Rev. A 99, 012334] Published Fri Jan 18, 2019

## Diffusive Heat Waves in Random Conformal Field Theory

Author(s): Edwin Langmann and Per Moosavi
We propose and study a conformal field theory (CFT) model with random position-dependent velocity that, as we argue, naturally emerges as an effective description of heat transport in one-dimensional quantum many-body systems with certain static random impurities. We present exact analytical results...
[Phys. Rev. Lett. 122, 020201] Published Fri Jan 18, 2019

## Dynamic Shear Suppression in Quantum Phase Space

Author(s): Maxime Oliva and Ole Steuernagel
Classical phase space flow is inviscid. Here we show that in quantum phase space Wigner’s probability current $\mathbf{J}$ can be effectively viscous. This results in shear suppression in quantum phase space dynamics which enforces Zurek’s limit for the minimum size scale of spotty structures that d...
[Phys. Rev. Lett. 122, 020401] Published Fri Jan 18, 2019