2026-06-28T20:35:53Zhttps://docta.ucm.es/rest/oai/request

oai:docta.ucm.es:20.500.14352/418982023-08-27T17:37:19Zcom_20.500.14352_14col_20.500.14352_15

The inverse eigenvalue problem for quantum channels Wolf, Michael Pérez García, David Given a list of n complex numbers, when can it be the spectrum of a quantum channel, i.e., a completely positive trace preserving map? We provide an explicit solution for the n=4 case and show that in general the characterization of the non-zero part of the spectrum can essentially be given in terms of its classical counterpart - the non-zero spectrum of a stochastic matrix. A detailed comparison between the classical and quantum case is given. We discuss applications of our findings in the analysis of time-series and correlation functions and provide a general characterization of the peripheral spectrum, i.e., the set of eigenvalues of modulus one. We show that while the peripheral eigen-system has the same structure for all Schwarz maps, the constraints imposed on the rest of the spectrum change immediately if one departs from complete positivity. 2023-06-20T00:04:36Z 2023-06-20T00:04:36Z 2010 journal article https://hdl.handle.net/20.500.14352/41898 http://arxiv.org/abs/1005.4545 eng QUEVADIS (233859) QUITEMAD-CM (S2009/ESP-1594) (MTM2008-01366) I-MATH COQUIT open access