| AVS 59th Annual International Symposium and Exhibition | |
| Electron Transport at the Nanoscale Focus Topic | Thursday Sessions |
| Session ET+NS+EM-ThM |
| Session: | Electron Transport at the Nanoscale: Nanowires and Junctions |
| Presenter: | S.Y. Qin, Oak Ridge National Laboratory |
| Authors: | S.Y. Qin, Oak Ridge National Laboratory T. Kim, Oak Ridge National Laboratory Y. Zhang, University of California Irvine W. Ouyang, University of California Irvine H. Weitering, The University of Tennessee C. Shih, The University of Texas at Austin A.P. Baddorf, Oak Ridge National Laboratory R. Wu, University of California Irvine A.-P. Li, Oak Ridge National Laboratory |
| Correspondent: | Click to Email |
Quantum wires are extremely narrow one-dimensional (1D) materials where electron motion is allowed only along the wire direction, and is confined in the other two directions. Quantum wires, as a smallest electronic conductor, are expected to be a fundamental component in all quantum electronic architectures. The electronic conductance in quantum wires, however, is often dictated by structural instabilities and electron localization at the atomic scale. Adding interwire coupling can often lead to the formation of change density waves. In both cases, the metallic state is not stable and a metal to insulator transition (MIT) occurs at low temperature. [1] Here we show that robust metallic conductance can be stabilized by interwire coupling, while the isolated single nanowires exhibit a MIT due to quantum localization.
We grow the quantum wires of GdSi2 on Si(100) and study the evolution of electronic transport as a function of temperature and interwire coupling as the quantum wires are self-assembled wire-by-wire. As shown in Fig. 1, individual nanowires have a width of 16.7 Å, a height of 4 Å, and lengths of micrometers. These nanowires can be grown either in the form of isolated nanowires or bundles with a number of constituent wires separated by an atomic interwire spacing. We perform the correlated study of electronic properties by utilizing both scanning tunneling microscopy and nanotransport measurements on the same nanowire. [2] The approach takes advantage of our developments in fabricating nanocontacts using a field-induced atom emission process to bridge the atomic wires and the mesoscopic transport electrodes. [3] A MIT is revealed in isolated nanowires, while a robust metallic state is obtained in wire bundles at low temperature. The results provide a rare glimpse of the intrinsic structure-transport relations and the influence of local environments at the atomic scale. This research was conducted at the Center for Nanophase Materials Sciences, which is sponsored at Oak Ridge National Laboratory by the Office of Basic Energy Sciences, U.S. Department of Energy.
1. Changgan Zeng, P.R.C. Kent, Tae-Hwan Kim, An-Ping Li, Hanno H. Weitering, Nature Materials, 7, 539 (2008).2. Shengyong Qin, Tae-Hwan Kim, Wenjie Ouyang, Yanning Zhang, Hanno H. Weitering, Chih-Kang Shih, Arthur P. Baddorf, Ruqian Wu, and An-Ping Li, Nano letters, 12 (2), 938 (2012).
3. Shengyong Qin, Sondra Hellstrom, Zhenan Bao, Boyan Boyanov, and An-Ping Li, Appl. Phys. Lett. 100 (11), 022211 (2012).