# All

## Complex charges, time reversal asymmetry, and interior-boundary conditions in quantum field theory

While fundamental physically realistic Hamiltonians should be invariant under time reversal, time
asymmetric Hamiltonians can occur as mathematical possibilities or effective Hamiltonians. Here, we
study conditions under which non-relativistic Hamiltonians involving particle creation and
annihilation, as come up in quantum field theory (QFT), are time asymmetric. It turns out that the
time reversal operator T can be more complicated than just complex conjugation, which leads to the

## Time-dependent Darboux (supersymmetric) transformations for non-Hermitian quantum systems

We propose time-dependent Darboux (supersymmetric) transformations that provide a scheme for the
calculation of explicitly time-dependent solvable non-Hermitian partner Hamiltonians. Together with
two Hermitian Hamilitonians the latter form a quadruple of Hamiltonians that are related by two
time-dependent Dyson equations and two intertwining relations in form of a commutative diagram. Our
construction is extended to the entire hierarchy of Hamiltonians obtained from time-dependent

## Long-distance continuous-variable measurement-device-independent quantum key distribution with discrete modulation

Author(s): Hong-Xin Ma, Peng Huang, Dong-Yun Bai, Tao Wang, Shi-Yu Wang, Wan-Su Bao, and Gui-Hua Zeng
We propose a long-distance continuous-variable measurement-device-independent quantum key distribution (CV-MDI-QKD) protocol with discrete modulation. This kind of discrete-modulated scheme has good compatibility with efficient error correction code, which leads to higher reconciliation efficiency e...
[Phys. Rev. A 99, 022322] Published Wed Feb 20, 2019

## Reduced Quantum Anomaly in a Quasi-Two-Dimensional Fermi Superfluid: Significance of the Confinement-Induced Effective Range of Interactions

Author(s): Hui Hu, Brendan C. Mulkerin, Umberto Toniolo, Lianyi He, and Xia-Ji Liu
A two-dimensional (2D) harmonically trapped interacting Fermi gas is anticipated to exhibit a quantum anomaly and possesses a breathing mode at frequencies different from a classical scale-invariant value ${ω}_{B}=2{ω}_{⊥}$, where ${ω}_{⊥}$ is the trapping frequency. The predicted maximum quantum an...
[Phys. Rev. Lett. 122, 070401] Published Wed Feb 20, 2019

## Enabling Computation of Correlation Bounds for Finite-Dimensional Quantum Systems via Symmetrization

Author(s): Armin Tavakoli, Denis Rosset, and Marc-Olivier Renou
We present a technique for reducing the computational requirements by several orders of magnitude in the evaluation of semidefinite relaxations for bounding the set of quantum correlations arising from finite-dimensional Hilbert spaces. The technique, which we make publicly available through a user-...
[Phys. Rev. Lett. 122, 070501] Published Wed Feb 20, 2019

## Relativistic chiral qubits, their time evolution, and correlations

Author(s): Jakub Rembieliński and Paweł Caban
We introduce and discuss the concept of chiral relativistic qubit as an irreducible amount of quantum information related to a one-half spin relativistic chiral elementary system (carrier particle). We propose a Lorentz-covariant time evolution of the qubit which on the level of the density matrix i...
[Phys. Rev. A 99, 022320] Published Wed Feb 20, 2019

## Measure of positive and not completely positive single-qubit Pauli maps

Author(s): Vinayak Jagadish, R. Srikanth, and Francesco Petruccione
The time evolution of an initially uncorrelated system is governed by a completely positive (CP) map. More generally, the system may contain initial (quantum) correlations with an environment, in which case the system evolves according to a not-completely positive (NCP) map. It is an interesting que...
[Phys. Rev. A 99, 022321] Published Wed Feb 20, 2019

## Eigenstate Thermalization, Random Matrix Theory, and Behemoths

Author(s): Ivan M. Khaymovich, Masudul Haque, and Paul A. McClarty
The eigenstate thermalization hypothesis (ETH) is one of the cornerstones of contemporary quantum statistical mechanics. The extent to which ETH holds for nonlocal operators is an open question that we partially address in this Letter. We report on the construction of highly nonlocal operators, behe...
[Phys. Rev. Lett. 122, 070601] Published Tue Feb 19, 2019

## Universal quantum gates between nitrogen-vacancy centers in a levitated nanodiamond

Author(s): Xing-Yan Chen and Zhang-qi Yin
We propose a scheme to realize the controlled-phase gates between nitrogen-vacancy (NV) centers in an optically trapped nanodiamond, through a uniform magnetic field-induced coupling between the NV centers and the torsional mode of the levitated nanodiamond. The gates are insensitive to the thermal ...
[Phys. Rev. A 99, 022319] Published Tue Feb 19, 2019

## Quantum channel simulation of phylogenetic branching models

Quantum channel simulations constructing probability tensors for biological multi-taxa in
phylogenetics are proposed. These are given in terms of positive trace preserving maps (quantum
channels), operating on quantum density matrices, using evolving systems of quantum walks with
multiple walkers. Simulation of a variety of standard phylogenetic branching models, applying on
trees of various topologies, is constructed using appropriate decoherent quantum circuits. For the