AUTHOR=Rahimifard Leila , Shylendra  Ahish , Nasrin  Shamma , Liu  Stephanie E. , Sangwan  Vinod K. , Hersam  Mark C. , Trivedi Amit Ranjan TITLE=Higher order neural processing with input-adaptive dynamic weights on MoS2 memtransistor crossbars JOURNAL=Frontiers in Electronic Materials VOLUME=2 YEAR=2022 URL=https://www.frontiersin.org/journals/electronic-materials/articles/10.3389/femat.2022.950487 DOI=10.3389/femat.2022.950487 ISSN=2673-9895 ABSTRACT=

The increasing complexity of deep learning systems has pushed conventional computing technologies to their limits. While the memristor is one of the prevailing technologies for deep learning acceleration, it is only suited for classical learning layers where only two operands, namely weights and inputs, are processed simultaneously. Meanwhile, to improve the computational efficiency of deep learning for emerging applications, a variety of non-traditional layers requiring concurrent processing of many operands are becoming popular. For example, hypernetworks improve their predictive robustness by simultaneously processing weights and inputs against the application context. Two-electrode memristor grids cannot directly map emerging layers’ higher-order multiplicative neural interactions. Addressing this unmet need, we present crossbar processing using dual-gated memtransistors based on two-dimensional semiconductor MoS2. Unlike the memristor, the resistance states of memtransistors can be persistently programmed and can be actively controlled by multiple gate electrodes. Thus, the discussed memtransistor crossbar enables several advanced inference architectures beyond a conventional passive crossbar. For example, we show that sneak paths can be effectively suppressed in memtransistor crossbars, whereas they limit size scalability in a passive memristor crossbar. Similarly, exploiting gate terminals to suppress crossbar weights dynamically reduces biasing power by ∼20% in memtransistor crossbars for a fully connected layer of AlexNet. On emerging layers such as hypernetworks, collocating multiple operations within the same crossbar cells reduces operating power by ∼15× on the considered network cases.