Special CPM Seminar

Stark effect control of spin rectification in a nanowire multi-dot system

Stefano Roddaro

Scuola Normale Superiore, Pisa

The control of orbital and spin state of single electrons is a key ingredient for quantum information processing, novel detection scheme and, more generally, is of much relevance for spintronics. Coulomb and spin blockade (SB) in double quantum dots (DQDs) enable advanced single-spin operations that would be available even for room-temperature applications for suffciently small devices. To date, however, spin operations in DQDs were observed at sub-Kelvin temperatures, a key reason being that scaling a DQD system while retaining an independent control on the individual dots is very challenging. I shall show that quantum-confined Stark effect allows an independent addressing of two dots only 5 nm apart with no need for aligned nanometer-size local gating and thus provides a scalable method to fully control a DQD device, regardless of its physical size. In the present implementation, I shall show InAs/InP nanowire (NW) DQDs that display an experimentally detectable SB up to 10 K. An unexpected re-entrant SB lifting as a function magnetic-field intensity will also be discussed.