Publications

2020
Y. Kalcheim, Camjayi, A., del Valle, J., Salev, P., Rozenberg, M., and Schuller, I. K., “Non-thermal resistive switching in Mott insulator nanowires”, vol. 11, no. 1, p. 2985, 2020. WebsiteAbstract
Resistive switching can be achieved in a Mott insulator by applying current/voltage, which triggers an insulator-metal transition (IMT). This phenomenon is key for understanding IMT physics and developing novel memory elements and brain-inspired technology. Despite this, the roles of electric field and Joule heating in the switching process remain controversial. Using nanowires of two archetypal Mott insulators—VO2 and V2O3 we unequivocally show that a purely non-thermal electrical IMT can occur in both materials. The mechanism behind this effect is identified as field-assisted carrier generation leading to a doping driven IMT. This effect can be controlled by similar means in both VO2 and V2O3, suggesting that the proposed mechanism is generally applicable to Mott insulators. The energy consumption associated with the non-thermal IMT is extremely low, rivaling that of state-of-the-art electronics and biological neurons. These findings pave the way towards highly energy-efficient applications of Mott insulators.
2018
C. Adda, et al., “First demonstration of ``Leaky Integrate and Fire{''} artificial neuron behavior on (V0.95Cr0.05)(2)O-3 thin film”, MRS COMMUNICATIONS, vol. 8, p. 835-841, 2018.Abstract
A great challenge in the field of neurocomputing is to mimic the brain behavior by implementing artificial synapses and neurons directly in hardware. This work shows that a Leaky Integrate and Fire (LIF) artificial neuron can be realized with a two-terminal device made of Mott insulator thin films. Polycrystalline thin films of the well-known Mott insulator oxide (V0.95Cr0.05)(2)O-3 were deposited by magnetron sputtering and patterned with micron-scale TIN electrodes. These devices exhibit a volatile resistive switching and a remarkable LIF behavior under a train of pulses suggesting that LIF artificial neurons may be realized from (V0.95Cr0.05)(2)O-3 thin films.
F. Tesler, et al., “Relaxation of a Spiking Mott Artificial Neuron”, PHYSICAL REVIEW APPLIED, vol. 10, p. 054001, 2018.Abstract
We consider the phenomenon of electric Mott transition (EMT), which is an electrically induced insulator-to-metal transition. Experimentally, it is observed that depending on the magnitude of the electric excitation, the final state may show a short-lived or a long-lived resistance change. We extend a previous model for the EMT to include the effect of local structural distortions through an elastic energy term. We find that by strong electric pulsing, the induced metastable phase may become further stabilized by the electroelastic effect. We present a systematic study of the model by numerical simulations and compare the results to experiments in Mott insulators of the AM(4)Q(8) family. Our work significantly extends the scope of our recently introduced leaky-integrate-and-fire Mott neuron {[}P. Stoliar et al., Adv. Funct. Mat. 27, 1604740 (2017)] to provide a better insight into the physical mechanism of its relaxation. This is a key feature for future implementations of neuromorphic circuits.