Searcharxiv⌕ Search

arXiv subjects

Mickel A. de Ponte

Publications and source records attributed to Mickel A. de Ponte.

2 recordsLinked to original sources

Shortening time scale to reduce thermal effects in quantum transistors

In this article, we present a quantum transistor model based on a network of coupled quantum oscillators destined to quantum information processing tasks in linear optics. To this end, we show in an analytical way how a set of $N$ quantum oscillators (data-bus) can be used as an optical quantum switch, in which the energy gap of the data bus oscillators plays the role of an adjustable "potential barrier". This enables us to "block or allow" the quantum information to flow from the source to the drain. In addition, we discuss how this device can be useful for implementing single qubit phase-shift quantum gates with high fidelity, so that it can be used as a useful tool. To conclude, during the study of the performance of our device when considering the interaction of this with a thermal reservoir, we highlight the important role played by the set of oscillators which constitute the data-bus in reducing the unwanted effects of the thermal reservoir. This is achieved by reducing the information exchange time (shortening time scale) between the desired oscillators. In particular, we have identified a non-trivial criterion in which the ideal size of the data-bus can be obtained so that it presents the best possible performance. We believe that our study can be perfectly adapted to a large number of thermal reservoir models.

quant-ph↗

Determining the eigenvalues of a square matrix through known information of its submatrix

In this paper we bring to light an unprecedented property of the eigenvalues of a matrix A with the eigenvalues and eigenvectors of a submatrix of A. This property can be used, through the technique developed here, to determine some of eigenvalues of A and, thus, reduce the degree of the characteristic polynomial associated with this matrix. This reduction can occur in two ways: when restrictions between some elements of A are checked (or imposed) and/or when some eigenvalues of the submatrix of A are degenerate. As an application, we show how to obtain matrices of arbitrary size, not trivial, that allow the algebraic calculation of eigenvalues and eigenvectors and how to share a set of eigenvectors of a submatrix of A with matrix A itself, preserving norm, direction and sense.

math.RA↗