Long-range crossed Andreev reflection in topological insulator nanowires proximitized by a superconductor
Fuente:
arXiv
Saved in:
| Main Authors: | , , , , , |
|---|---|
| Format: | Preprint |
| Published: |
2024
|
| Subjects: | |
| Online Access: | |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1866911111769489408 |
|---|---|
| author | Feng, Junya Legg, Henry F. Bagchi, Mahasweta Loss, Daniel Klinovaja, Jelena Ando, Yoichi |
| author_facet | Feng, Junya Legg, Henry F. Bagchi, Mahasweta Loss, Daniel Klinovaja, Jelena Ando, Yoichi |
| contents | Crossed Andreev reflection (CAR) is a nonlocal transport phenomenon that creates/detects Cooper-pair correlations between distant places. It is also the basis of Cooper-pair splitting to generate remote entanglement. Although CAR has been extensively studied in semiconductors proximity-coupled to a superconductor, it has been very difficult to observe it in a topological insulator (TI). Here we report the first observation of CAR in a proximitized TI nanowire (TINW). We performed local and nonlocal conductance spectroscopy on mesoscopic TINW devices in which superconducting (Nb) and metallic (Pt/Au) contacts are made on a bulk-insulating TINW. The local conductance detected a hard gap, accompanied by the appearance of Andreev bound states that can reach zero-bias, while a negative nonlocal conductance was occasionally observed upon sweeping the chemical potential, giving evidence for CAR. Surprisingly, the CAR signal was detected even over 1.5 $μ$m, which implies that pair correlations extend over a length scale much longer than the expected superconducting coherence length of either Nb or the proximitised TINW. Such a long-range CAR effect is possibly due to an intricate role of disorder in proximitized nanowires. Also, our 0.9-$μ$m device presented a decent Cooper-pair splitting efficiency of up to 0.5. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2407_02383 |
| institution | arXiv |
| publishDate | 2024 |
| record_format | arxiv |
| spellingShingle | Long-range crossed Andreev reflection in topological insulator nanowires proximitized by a superconductor Feng, Junya Legg, Henry F. Bagchi, Mahasweta Loss, Daniel Klinovaja, Jelena Ando, Yoichi Mesoscale and Nanoscale Physics Materials Science Strongly Correlated Electrons Superconductivity Crossed Andreev reflection (CAR) is a nonlocal transport phenomenon that creates/detects Cooper-pair correlations between distant places. It is also the basis of Cooper-pair splitting to generate remote entanglement. Although CAR has been extensively studied in semiconductors proximity-coupled to a superconductor, it has been very difficult to observe it in a topological insulator (TI). Here we report the first observation of CAR in a proximitized TI nanowire (TINW). We performed local and nonlocal conductance spectroscopy on mesoscopic TINW devices in which superconducting (Nb) and metallic (Pt/Au) contacts are made on a bulk-insulating TINW. The local conductance detected a hard gap, accompanied by the appearance of Andreev bound states that can reach zero-bias, while a negative nonlocal conductance was occasionally observed upon sweeping the chemical potential, giving evidence for CAR. Surprisingly, the CAR signal was detected even over 1.5 $μ$m, which implies that pair correlations extend over a length scale much longer than the expected superconducting coherence length of either Nb or the proximitised TINW. Such a long-range CAR effect is possibly due to an intricate role of disorder in proximitized nanowires. Also, our 0.9-$μ$m device presented a decent Cooper-pair splitting efficiency of up to 0.5. |
| title | Long-range crossed Andreev reflection in topological insulator nanowires proximitized by a superconductor |
| topic | Mesoscale and Nanoscale Physics Materials Science Strongly Correlated Electrons Superconductivity |
| url | https://arxiv.org/abs/2407.02383 |