Andreev Billards
Andreev Billards

Scanning electron microscope image of an array of circular Andreev billiards (Au, diameter 200 nm surrounded by Nb)

We investigated the LDOS of artificially fabricated normal metal nano-structures (Au) in contact with a superconductor (Nb). Local spectroscopic measurements revealed the presence of well defined sub-gap peaks at various positions of the STM tip. The peak features suggest they originate from quasi-particle bound states within the normal-metal structures (De Gennes St James states). Refocusing of electronic trajectories induced by the granular structure of the samples can explain the observation of spatially uncorrelated interference effects in a non-ballistic medium[2].

[2] Ballistic effects in a proximity induced superconducting diffusive metal W. Escoffier, C. Chapelier, , F. Lefloch
To be published in Phys. Rev. B Rapid Com.

Andreev Billards

Localized bound states in the LDOS of a square Andreev billiard measured at 60 mK for different positions of the STM tip.

Last update : 05/27 2009 (473)


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