Traditionally, skyrmions are treated as continuum magnetic textures of classical spins with a well-defined topological skyrmion number. Owing to their protection, have attracted great interest building blocks in future memory technology. Smaller offer greater density, however, quantum effects not negligible for sizes just few lattice constants. In this paper we study fluctuations around dense c...

We present a new proof of the quantum Cramer-Rao bound for precision parameter estimation [1–3] and extend it to a more general class of measurement procedures. We analyze a generalized framework for parameter estimation that covers most experimentally accessible situations, where multiple rounds of measurements, auxiliary systems or external control of the evolution are available. The proof pr...

We study a two-spin quantum Turing architecture, in which discrete local rotations {αm} of the Turing head spin alternate with quantum controlled NOT-operations. Substitution sequences are known to underlie aperiodic structures. We show that parameter inputs {αm} described by such sequences can lead here to a quantum dynamics, intermediate between the regular and the chaotic variant. Exponentia...

The statistical consequences of minimal length supposition are investigated for a canonical ensemble of ideal gas. These effects are encoded in the so-called Generalized Uncertainty Principle (GUP) of the second order. In the frame work of the considered GUP scenario, a unique partition function is obtained by using of two different methods of quantum and classical approaches. It should be noti...

Abstract Recently, IBM has made available a quantum computer provided with 16 qubits, denoted as IBM Q16. Previously, only a 5 qubit device, denoted as Q5, was available. Both IBM devices can be used to run quantum programs, by means of a cloud-based platform. In this paper, we illustrate our experience with IBM Q16 in demonstrating entanglement assisted invariance, also known as envariance, an...

Carbon quantum dots (CQDs) serve as a new class of ‘zero dimensional’ nanomaterial’s in thecarbon class with sizes below 10 nm. As light emitting nanocrystals, QDs are assembled from semiconductormaterials, from the elements in the periodic groups of II-VI, III-V or IV-VI, mainly thanks to impacts of quantum confinement QDs have unique optical properties such as brighter, highly pho...

Generalizing earlier work characterizing the quantum query complexity of computing a function of an unknown classical “black box” function drawn from some set of such black box functions, we investigate a more general quantum query model in which the goal is to compute functions of N×N “black box” unitary matrices drawn from a set of such matrices, a problem with applications to determining pro...

We show that although unconditionally secure quantum bit commitment is impossible, it can be based upon any family of quantum one-way permutations. The resulting scheme is unconditionally concealing and computationally binding. Unlike the classical reduction of Naor, Ostrovski, Ventkatesen and Young, our protocol is non-interactive and has communication complexity O(n) qubits for n a security p...

In this paper we show how to convert a statistically binding but computationally concealing quantum bit commitment scheme into a computationally binding but statistically concealing qbc scheme. For a security parameter n, the construction of the statistically concealing scheme requires O(n) executions of the statistically binding scheme. As a consequence, statistically concealing but computatio...

In this paper we show how to convert a statistically binding but computationally concealing quantum bit commitment scheme into a computationally binding but statistically concealing scheme. For a security parameter n, the construction of the statistically concealing scheme requires O(n) executions of the statistically binding scheme. As a consequence, statistically concealing but computationall...