Author(s): Christopher T. Chubb, Marco Tomamichel, and Kamil Korzekwa
We consider the problem of interconverting a finite amount of resources within all theories whose single-shot transformation rules are based on a majorization relation, e.g., the resource theories of entanglement and coherence (for pure-state transformations), as well as thermodynamics (for energy-i...
[Phys. Rev. A 99, 032332] Published Fri Mar 22, 2019

Author(s): Kamil Korzekwa, Christopher T. Chubb, and Marco Tomamichel
We identify and explore the intriguing property of resource resonance arising within resource theories of entanglement, coherence, and thermodynamics. While the theories considered are reversible asymptotically, the same is generally not true in realistic scenarios where the available resources are ...
[Phys. Rev. Lett. 122, 110403] Published Fri Mar 22, 2019

Author(s): Steven Mathey and Sebastian Diehl
We address the nature of phase transitions in periodically driven systems coupled to a bath. The latter enables a synchronized nonequilibrium Floquet steady state at finite entropy, which we analyze for rapid drives within a nonequilibrium renormalization group (RG) approach. While the infinitely ra...
[Phys. Rev. Lett. 122, 110602] Published Fri Mar 22, 2019

Author(s): Ivan Šupić, Paul Skrzypczyk, and Daniel Cavalcanti
Quantum state teleportation is a protocol where a shared entangled state is used as a quantum channel to transmit quantum information between distinct locations. Here we consider the task of estimating entanglement of the underlying shared state in teleportation protocols. We show that the data acce...
[Phys. Rev. A 99, 032334] Published Fri Mar 22, 2019

Author(s): Fabian Ewert and Peter van Loock
Reliable entangling gates for qubits encoded in single-photon states represent a major challenge on the road to scalable quantum computing architectures based on linear optics. In this work, we present two approaches to develop high-fidelity, near-deterministic controlled-sign-shift gates based on t...
[Phys. Rev. A 99, 032333] Published Fri Mar 22, 2019

Author(s): Yu Liu, Jiazhao Tian, Ralf Betzholz, and Jianming Cai
We propose a novel strategy to reconstruct the quantum state of dark systems, i.e., degrees of freedom that are not directly accessible for measurement or control. Our scheme relies on the quantum control of a two-level probe that exerts a state-dependent potential on the dark system. Using a sequen...
[Phys. Rev. Lett. 122, 110406] Published Thu Mar 21, 2019

Author(s): Maria Schuld, Ville Bergholm, Christian Gogolin, Josh Izaac, and Nathan Killoran
An important application for near-term quantum computing lies in optimization tasks, with applications ranging from quantum chemistry and drug discovery to machine learning. In many settings, most prominently in so-called parametrized or variational algorithms, the objective function is a result of ...
[Phys. Rev. A 99, 032331] Published Thu Mar 21, 2019

Author(s): Riccardo Rota, Fabrizio Minganti, Cristiano Ciuti, and Vincenzo Savona
We study an array of coupled optical cavities in the presence of two-photon driving and dissipation. The system displays a critical behavior similar to that of a quantum Ising model at finite temperature. Using the corner-space renormalization method, we compute the steady-state properties of finite...
[Phys. Rev. Lett. 122, 110405] Published Thu Mar 21, 2019

The externally driven nonlinear Dirac (NLD) equation with scalar-scalar self-interaction studied in
(2016 J. Phys. A: Math. Theor . 49 065402) is revisited. By using a variational method and an ansatz
with five collective coordinates, the dynamics of the NLD solitons is well described. It is shown
that this new ansatz possesses certain advantages, namely the canonical momentum agrees with the
field momentum, the energy associated to the collective coordinate equations agrees with the energy

Quasi-monochromatic complex reductions of a number of physically important equations are obtained.
Starting from the cubic nonlinear Klein–Gordon (NLKG), the Korteweg–de Vries (KdV) and water wave
equations, it is shown that the leading order asymptotic approximation can be transformed to the
well-known integrable AKNS system (Ablowitz et al 1974 Stud. Appl. Math . 53 249) associated with
second order (in space) nonlinear wave equations. This in turn establishes, for the first time, an