تقرير
Entanglement between quasiparticles in superconducting islands mediated by a single spin
العنوان: | Entanglement between quasiparticles in superconducting islands mediated by a single spin |
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المؤلفون: | Saldaña, Juan Carlos Estrada, Vekris, Alexandros, Pavešič, Luka, Žitko, Rok, Grove-Rasmussen, Kasper, Nygård, Jesper |
سنة النشر: | 2022 |
المجموعة: | Condensed Matter |
مصطلحات موضوعية: | Condensed Matter - Mesoscale and Nanoscale Physics, Condensed Matter - Strongly Correlated Electrons, Condensed Matter - Superconductivity |
الوصف: | Condensed matter is composed of a small set of identical units, yet it shows an immense range of behaviour. Recently, an array of cold atoms was used to generate long-range quantum entanglement, a property of topological matter. Another approach to strong non-local correlations employs the macroscopic coherence of superconductors. Impurity spins in superconductors are thought to be unamenable to the formation of long-range spin entanglement because each spin tends to be screened by binding to a quasiparticle from the superconductor to form a local singlet. Here we demonstrate that it is possible to attach a second quasiparticle to the spin, overscreening it into a doublet state carrying ferromagnetic correlations between two quasiparticles over a micrometer distance. To demonstrate this effect, which is strongest for equal binding, we symmetrically couple the spin of a quantum dot to two ultrasmall superconducting islands. The overscreened state requires sufficiently large Coulomb repulsion and exchange binding to become well defined. We predict that this state will carry long-range correlations for an alternating chain of quantum dots and superconducting islands, opening a new route to controllable large-scale entanglement in the solid state. Comment: 4 figures, 7 extended data figures |
نوع الوثيقة: | Working Paper |
URL الوصول: | http://arxiv.org/abs/2203.00104 |
رقم الأكسشن: | edsarx.2203.00104 |
قاعدة البيانات: | arXiv |
الوصف غير متاح. |