Two-Qubits in a Large-<i>S</i> Environment

• Main Authors: Eliana Fiorelli, Alessandro Cuccoli, Paola Verrucchi
• Format: Article
• Language: English
• Published: MDPI AG 2019-06-01
• Series: Proceedings
• Subjects: entanglement; quantum devices; environment
• Online Access: https://www.mdpi.com/2504-3900/12/1/10

We analytically express the loss of entanglement between the components of a quantum device due to the generation of quantum correlations with its environment, and show that such loss diminishes when the latter is macroscopic and displays a semi-classical behaviour. We model the problem as a device made of a couple of qubits with a magnetic environment: this choice allows us to implement the above condition of semi-classical macroscopicity in terms of a large-<i>S</i> condition, according to the well known equivalence between classical and <inline-formula> <math display="inline"> <semantics> <mrow> <mi>S</mi> <mo>&#8594;</mo> <mi>&#8734;</mi> </mrow> </semantics> </math> </inline-formula> limit. A possible strategy for protecting internal entanglement exploiting the mechanism of domain-formation typical of critical dynamics is also suggested.