Events in Physics
Charles Smith (Cavendish Lab) - Low temperature scanned gate imaging of quantum phenomena in nano-devices
Semiconductor Physics group, Cavendish Laboratory, J. J. Thomson Avenue, Cambridge, CB3 OHE
Scanned gate techniques allow the spatial variation of physical phenomena to be imaged at low temperatures. The technique uses a conducting scanning probe tip with a voltage applied to it as a local gate to change the transport through an underlying device. Images are created where the contrast comes from a change in the transport though the device as a function of tip position. I will introduce the background work in this field, which was developed on IIIV heterostructure devices, and then move on to discuss recent research on imaging graphene devices. Recent work imaging how single and bi-layer graphene on silicon carbide alters the quantum Hall effect will be discussed as well as more recent work on imaging of magnetically focussed beams of electrons in high mobility graphene on boron nitride, and the effects of doping and disorder on transport in graphene nano-devices.
Imaging ballistic carrier trajectories in graphene using scanning gate microscopy
Sei Morikawa, Ziwei Dou, Shu-Wei Wang, Charles G Smith, Kenji Watanabe, Takashi Taniguchi, Satoru Masubuchi, Tomoki Machida, Malcolm R Connolly, Applied Physics Letters 107 (24), 243102. (2015)
Quantum Hall effect and quantum point contact in bilayer-patched epitaxial graphene
Cassandra Chua, Malcolm Connolly, Arseniy Lartsev, Tom Yager, Samuel Lara-Avila, Sergey Kubatkin, Sergey Kopylov, Vladimir Fal’ko, Rositza Yakimova, Ruth Pearce, TJBM Janssen, Alexander Tzalenchuk, Charles G Smith. Nano letters 14 (6), 3369-3373. (2014)