2134/21047
Wei Yi
Wei
Yi
Sergey Saveliev
Sergey
Saveliev
Gilberto Medeiros-Ribeiro
Gilberto
Medeiros-Ribeiro
Feng Miao
Feng
Miao
M.-X. Zhang
M.-X.
Zhang
J. Joshua Yang
J. Joshua
Yang
A.M. Bratkovsky
A.M.
Bratkovsky
R.S. Williams
R.S.
Williams
Quantized conductance coincides with state instability and excess noise in tantalum oxide memristors
Loughborough University
2016
untagged
Physical Sciences not elsewhere classified
2016-04-25 09:40:57
Journal contribution
https://repository.lboro.ac.uk/articles/journal_contribution/Quantized_conductance_coincides_with_state_instability_and_excess_noise_in_tantalum_oxide_memristors/9408773
Tantalum oxide memristors can switch continuously from a low-conductance semiconducting to a high-conductance metallic state. At the boundary between these two regimes are quantized conductance states, which indicate the formation of a point contact within the oxide characterized by multistable conductance fluctuations and enlarged electronic noise. Here, we observe diverse conductance-dependent noise spectra, including a transition from 1/f 2 (activated transport) to 1/f (flicker noise) as a function of the frequency f, and a large peak in the noise amplitude at the conductance quantum GQ¼2e2/h, in contrast to
suppressed noise at the conductance quantum observed in other systems. We model the
stochastic behaviour near the point contact regime using Molecular Dynamics–Langevin
simulations and understand the observed frequency-dependent noise behaviour in terms of thermally activated atomic-scale fluctuations that make and break a quantum conductance channel. These results provide insights into switching mechanisms and guidance to device operating ranges for different applications.