Magnetization near a constriction between BCS superconductors by spin-dependent tunneling
| Autor: | Entin-Wohlman, O., Shekhter, R. I., Jonson, M., Aharony, A. |
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| Rok vydání: | 2023 |
| Předmět: | |
| Zdroj: | Phys. Rev. B 108, L180501 (2023) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevB.108.L180501 |
| Popis: | Spin-dependent electron tunneling through a voltage-biased micro-constriction between two bulk superconductors is shown to create a static magnetization near the constriction and an ac Josephson-like spin current. Although spin-dependent tunneling generates quantum spin fluctuations even in the absence of a bias, the formation of spin-triplet Cooper pairs necessary for the creation of magnetization is blocked by destructive interference between different quasi-electron and quasi-hole tunneling channels, unless there is an asymmetry between the tunneling densities of states for electrons and holes. Breaking the symmetry in the electron-hole tunnel density of states and creating electron-hole tunneling imbalance by biasing the device destroys the destructive interference and enables triplet Cooper-pair formation. As a result, magnetizing the superconductor becomes possible. The role of the voltage in lifting the blockade hindering the spin-triplet Cooper pair formation is an example of an electrically-controlled dissipation-less spintronic phenomenon. Comment: Changed title, added figures, published version |
| Databáze: | arXiv |
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