Title: Anomaly in Quantized Conductance in Quasi-1D Metallic Quantum Wire beyond the Landauer model
Speaker: Prof. Mukunda Das, Department of Theoretical Physics, RSPE, The Australian National University, Canberra, Australia
Venue: IoP lecture Hall
Date: 2018-Dec-12 16:00:00
Abstract: We study the quantized conductance of quasi-1D metallic quantum wire, where it has been observed to have a striking departure from the canonical quantized step sequence. As per general understanding each independent sub-band structure provides a Landauer conductance quantum based on coherent single carrier transmission. The observed enhanced conductance depends on applied source-drain bias and is beyond the Landauer limit, seems as a second anomaly. The first one is studied extensively known as 0.7 conductance anomaly (see our earlier work in Adv. Nat. Sci.: Nanosci. Nanotechnol. 8 023001 (2017). In order to understand the second anomaly we employ quantum kinetic approach by including inter-sub-band contribution (J. Phys.: Condens Matter 30 385304 (2018)). We argue that the elevated conductance plateau is inherently nonlinear.
It is extremely flat and exceeds Landauer’s upper bound violating the unitarity limit of linear response theory.
