Observation of strong spin-orbit interaction in 2DEG in an InAs heterostructure grown on GaAs substrate

Narrow-gap semiconductors such as InAs or InSb are known for their strong spin-orbit interactions. Therefore, heterostructure such as InAs/AlInAs is an attractive system for its potential applications to spin FETs. If the heterostructure is homoepitaxially grown on p-InAs substrate, the high crystal quality is expected and hence the high mobility and enhanced spin-orbit interaction. However, the InAs heterostructure grown on InAs is intrinsically suffered from the substrate leak current due to its narrow-gap nature. Here we report the strained growth and characterization of InAs/AlInAs heterostructure on GaAs substrate by molecular beam epitaxy (MBE) and show that the strong spin-orbit interaction is obtained while substrate leakage current is substantially suppressed.