Partitioned density matrices and entanglement correlators
| Autor: | T. Cox, P. C. E. Stamp |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
Density matrix
Physics Quantum Physics Differential equation FOS: Physical sciences Equations of motion 02 engineering and technology Quantum entanglement 021001 nanoscience & nanotechnology 01 natural sciences Condensed Matter - Other Condensed Matter Qubit 0103 physical sciences Quantum system Quantum field theory Quantum Physics (quant-ph) 010306 general physics 0210 nano-technology Other Condensed Matter (cond-mat.other) Spin-½ Mathematical physics |
| Zdroj: | Physical Review A. 98 |
| ISSN: | 2469-9934 2469-9926 |
| DOI: | 10.1103/physreva.98.062110 |
| Popis: | The density matrix of a non-relativistic quantum system, divided into $N$ sub-systems, is rewritten in terms of the set of all partitioned density matrices for the system. For the case where the different sub-systems are distinguishable, we derive a hierarchy of equations of motion linking the dynamics of all the partitioned density matrices, analogous to the "Schwinger-Dyson" hierarchy in quantum field theory. The special case of a set of $N$ coupled spin-$1/2$ "qubits" is worked out in detail. The equations are then rewritten in terms of a set of "entanglement correlators", which comprise all the possible correlation functions for the system - this case is worked out for coupled spin systems. The equations of motion for these correlators can be written in terms of a first-order differential equation for an entanglement correlator supervector. |
| Databáze: | OpenAIRE |
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