Details

Autor(en) / Beteiligte

• Zhang, Shu-feng
• Zhang, Tian-yi

Titel

A Perfect Andreev Reflection Induced by Anderson Disorder in a Normal–Superconductor Junction

Ist Teil von

• physica status solidi (b), 2021-08, Vol.258 (8), p.n/a

Erscheinungsjahr

2021

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• The electronic transport properties of a 2D normal metal superconductor are studied by a nonequilibrium Green's function method. The normal metal is the non‐inverted HgTe/CdTe quantum well doped by electrons. It is found that Andreev reflection (AR) is enhanced in the weak disorder regime while weakened in the strong disorder regime. However, the AR coefficient can be perfect ( T A = 1 ) with vanished fluctuations in the moderate disorder regime, whereas other scattering processes are forbidden. The mechanism goes that Anderson disorder leads to a topological Anderson insulator with bulk states localized while edge states still extensive. Multiple ARs and spin‐momentum locking cooperate to vanish the normal reflection and leave AR only. A detailed numerical study shows that fixing the Fermi surface in conduction band, a large enough junction width, and a strong coupling between the normal and superconducting leads are necessary for perfect AR. Andreev reflection (AR) is usually accompanied by the normal electron reflection in a conventional normal–superconductor (NS) junction. Herein, it is proposed that a perfect AR can be induced by Anderson disorder in an NS junction of the non‐inverted HgTe/CdTe quantum well in spite of barrier and momentum mismatch, because multiple ARs occur at the interface.