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Author(s): A. Bolt, D. Poulin, and T. M. Stace
Foliated quantum codes are a resource for fault-tolerant measurement-based quantum error correction for quantum repeaters and for quantum computation. They represent a general approach to integrating a range of possible quantum error correcting codes into larger fault-tolerant networks. Here, we pre...
[Phys. Rev. A 98, 062302] Published Mon Dec 03, 2018

Author(s): Ignacio Perito, Augusto J. Roncaglia, and Ariel Bendersky
The characterization of quantum processes is a key tool in quantum information processing tasks for several reasons: on one hand, it allows one to acknowledge errors in the implementations of quantum algorithms; on the other, it allows one to characterize unknown processes occurring in nature. Bende...
[Phys. Rev. A 98, 062303] Published Mon Dec 03, 2018

Author(s): Ranjith Nair
The problem of estimating multiple loss parameters of an optical system using the most general ancilla-assisted parallel strategy is solved under energy constraints. An upper bound on the quantum Fisher information matrix is derived assuming that the environment modes involved in the loss interactio...
[Phys. Rev. Lett. 121, 230801] Published Mon Dec 03, 2018

Author(s): Anindita Bera, Shiladitya Mal, Aditi Sen(De), and Ujjwal Sen
We investigate sharing of bipartite entanglement in a scenario where half of an entangled pair is possessed and projectively measured by one observer, called Alice, while the other half is subjected to measurements performed sequentially, independently, and unsharply, by multiple observers, called B...
[Phys. Rev. A 98, 062304] Published Mon Dec 03, 2018

Author(s): Shane Mansfield and Elham Kashefi
We introduce a notion of contextuality for transformations in sequential contexts, distinct from the Bell-Kochen-Specker and Spekkens notions of contextuality. Within a transformation-based model for quantum computation we show that strong sequential-transformation contextuality is necessary and suf...
[Phys. Rev. Lett. 121, 230401] Published Mon Dec 03, 2018

We study a system of penetrable bosons on a line, focusing on the high-density/weak-interaction
regime, where the ground state is, to a good approximation, a condensate. Under compression, the
system clusterizes at zero temperature, i.e. particles gather together in separate, equally
populated bunches. We compare predictions from the Gross–Pitaevskii (GP) equation with those of two
distinct variational approximations of the single-particle state, written as either a sum of

A theoretical description for particle coagulation due to Brownian motion combined with coalescence
is presented and experimentally verified. The present theory confirms that the particle-size
distribution function possesses a universal state, which is described by the self-similar kinetic
equation. A complete analytical solution of this integro-differential equation is found in the case
of Brownian coagulation mechanism. An explicit analytical particle-size distribution function,

We study generalized diffusion-wave equation in which the second order time derivative is replaced
by an integro-differential operator. It yields time fractional and distributed order time fractional
diffusion-wave equations as particular cases. We consider different memory kernels of the
integro-differential operator, derive corresponding fundamental solutions, specify the conditions of
their non-negativity and calculate the mean squared displacement for all cases. In particular, we

Superoscillatory functions—band-limited functions with local oscillations faster than their fastest
Fourier components—are extended to families that are ‘leaky’—not band-limited—but possess the same
local oscillations. Two different extensions are presented. For deterministic functions, the
prototype superoscillatory function is embedded in a leaky one-parameter family that can be studied
in detail analytically. For Gaussian random superoscillatory functions, the coefficients in the

We propose an encoding for topological quantum computation utilizing quantum representations of
mapping class groups. Leakage into a non-computational subspace seems to be unavoidable for
universality. We are interested in the possible gate sets which can emerge in this setting. As a
first step, we prove that for abelian anyons, all gates from these mapping class group
representations are normalizer gates. Results of Van den Nest then allow us to conclude that for