| Journal: | Brazilian journal of physics |
| Database: | PERIÓDICA |
| System number: | 000389441 |
| ISSN: | 0103-9733 |
| Authors: | Maziero, Jonas1 |
| Institutions: | 1Universidade Federal de Santa Maria, Centro de Ciencias Naturais e Exatas, Santa Maria, Rio Grande do Sul. Brasil |
| Year: | 2015 |
| Season: | Dic |
| Volumen: | 45 |
| Number: | 6 |
| Pages: | 575-583 |
| Country: | Brasil |
| Language: | Inglés |
| Document type: | Artículo |
| Approach: | Experimental, aplicado |
| English abstract | The numerical generation of random quantum states (RQS) is an important procedure for investigations in quantum information science. Here, we review some methods that may be used for performing that task. We start by presenting a simple procedure for generating random state vectors, for which the main tool is the random sampling of unbiased discrete probability distributions (DPD). Afterwards, the creation of random density matrices is addressed. In this context, we first present the standard method, which consists in using the spectral decomposition of a quantum state for getting RQS from random DPDs and random unitary matrices. In the sequence, the Bloch vector parametrization method is described. This approach, despite being useful in several instances, is not in general convenient for RQS generation. In the last part of the article, we regard the overparametrized method (OPM) and the related Ginibre and Bures techniques. The OPM can be used to create random positive semidefinite matrices with unit trace from randomly produced general complex matrices in a simple way that is friendly for numerical implementations. We consider a physically relevant issue related to the possible domains that may be used for the real and imaginary parts of the elements of such general complex matrices. Subsequently, a too fast concentration of measure in the quantum state space that appears in this parametrization is noticed |
| Disciplines: | Física y astronomía |
| Keyword: | Física atómica y molecular, Estados cuánticos aleatorios, Generación numérica, Método de sobreparametrización |
| Keyword: | Physics and astronomy, Atomic and molecular physics, Random quantum states, Numerical generation, Overparametrized method |
| Full text: | Texto completo (Ver PDF) |
