Non-monotonicity of Trace Distance Under Tensor Products



Document title: Non-monotonicity of Trace Distance Under Tensor Products
Journal: Brazilian journal of physics
Database: PERIÓDICA
System number: 000389437
ISSN: 0103-9733
Authors: 1
Institutions: 1Universidade Federal de Santa Maria, Departamento de Fisica, Santa Maria, Rio Grande do Sul. Brasil
Year:
Season: Oct
Volumen: 45
Number: 5
Pages: 560-566
Country: Brasil
Language: Inglés
Document type: Artículo
Approach: Experimental, aplicado
English abstract The trace distance (TD) possesses several of the good properties required for a faithful distance measure in the quantum state space. Despite its importance and ubiquitous use in quantum information science, one of its questionable features, its possible non-monotonicity under taking tensor products of its arguments (NMuTP), has been hitherto unexplored. In this article, we advance analytical and numerical investigations of this issue considering different classes of states living in a discrete and finite dimensional Hilbert space. Our results reveal that although this property of TD does not show up for pure states and for some particular classes of mixed states, it is present in a non-negligible fraction of the regarded density operators. Hence, even though the percentage of quartets of states leading to the NMuTP drawback of TD and its strength decrease as the system’s dimension grows, this property of TD must be taken into account before using it as a figure of merit for distinguishing mixed quantum states
Disciplines: Física y astronomía
Keyword: Física atómica y molecular,
Distancia cuántica,
Medición,
Distancia de rastreo,
Producto tensorial
Keyword: Physics and astronomy,
Atomic and molecular physics,
Quantum distance,
Measurement,
Trace distance,
Tensor product
Full text: Texto completo (Ver PDF)