Novel nanoelectronic devices

Jonathan Bird

Dr. Bird joined the EE faculty at UB in Fall 2004, under the auspices of a $750,000 Faculty Development Grant from NYSTAR. Research in Prof. Bird's group is focused on the study of novel nanoelectronic devices, with emphasis on the potential applications of these structures. His research is supported through multiple awards from the Department of Energy, the Office of Naval Research, and the National Science Foundation. Topics currently being explored in his group include:

Electron-Wave Approaches to Quantum Computing

Prof. Bird's group is studying the use of coupled quantum wires as a means to realize a scalable, solid-state based, qubit for use in quantum computing. They have recently been successful in providing a demonstration of a quantum NOT gate in this system.

SEM image of a device used to study electron switching. The device is realized on a high-mobility GaAs quantum well and the metal gates (lighter regions) define two quantum wires with a small coupling window (150 nm in the image shown)

Spin Transport in Semiconductor Nanostructures

This research investigates the unique features of spin-polarized electron transport in nonmagnetic semiconductor nanostructures, in which spin phenomena arise due to the increased importance of many-body interactions in confined electron systems. A recent highlight of this work, which was featured in Science , has been the use of coupled quantum wires to electrically readout the formation of a spin-polarized state in quantum wires. Current work seeks to extend these advances to develop a solid-state, spin-based, approach to quantum computing.

Device used for detection of spin polarization in quantum wires. The device consists of two quantum wires coupled by a quantum dot. The formation of a spin-polarized electron system in one wire is then detected in a measurement of the conductance of the other wire. The central quantum dot is 750 nm in size.

Hybrid Semiconductor NanoMagnetoElectronic Devices

This work seeks to integrate nanoscale magnetic elements with semiconductor nanostructures to realize functionalities such as giant magneto-resistance and magnetic memory. While there has been much work on the development of metallic magnetoelectronic devices in the literature, this work seeks to achieve similar functionality in planar semiconductor structures, compatible with existing integrated-circuit architectures.

Epitaxial Silicide Nanowires for Nanoelectronics

This multi-investigator project is focused on exploring the electronic properties, and potential applications, of self-assembled silicide nanowires.

Details of Dr. Bird's research can be found in some of his recent publications:

• T. Morimoto, Y. Iwase, N. Aoki, T. Sasaki, Y. Ochiai, A. Shailos, J. P. Bird, M. P. Lilly, J. L. Reno, and J. A. Simmons, “Nonlocal resonant interaction between coupled quantum wires”, Appl. Phys. Lett. 82 , 3952 – 3954 (2003).
• V. I. Puller, L. G. Mourokh, A. Shailos, and J. P. Bird, “Detection of local-moment formation using the resonant interaction between coupled quantum wires”, Phys. Rev. Lett. 92 , 96802 (2004) .
• J. P. Bird and Y. Ochiai, “Electron spin polarization in nanoscale constrictions”, Science 303 , 1621 – 1622 (2004).
• J.-F. Song, J. P. Bird, and Y. Ochiai, “Manipulating the transmission of a two-dimensional electron gas via spatially-varying magnetic fields”, Appl. Phys. Lett. 86 062106 (2005).
• J.-F. Lin, J. P. Bird, Zhian-He, P. A. Bennett, and D. J. Smith, “Signatures of quantum transport in self-assembled epitaxial nickel silicide nanowires”, Appl. Phys. Lett. 85 , 281 – 283 (2004).