Novel nanoelectronic devices based on emerging multifunctional materials such as ferroelectrics, antiferroelectrics, and complex oxides could enable unprecedented performance gains and novel functionalities in post-CMOS paradigms of computing. In this talk, I will start with the particular example of the negative capacitance field-effect transistor--a fundamentally new type of transistor--which could operate at a power significantly lower than the physical limit for its traditional CMOS counterparts. I will give an overview of the exciting developments in the field of negative capacitance over the past six years starting from the theoretical prediction in 2008 to the clean experimental demonstration of this phenomenon in archetypal ferroelectric oxides in 2015. I will then discuss our recent experimental work on negative capacitance transistors and the possible future directions using alternative negative capacitance materials such as antiferroelectric oxides. The negative capacitance phenomenon originates due to the nonlinear dynamics and instabilities in ferroelectrics and antiferroelectrics. These characteristics could also bring in new, unparalleled functionalities for alternative information processing platforms. I will conclude with two specific examples in this direction, namely (1) DC voltage amplification in purely passive heterostructures and circuits and (2) brain-like, neuroplastic responses in complex oxide devices.
Asif Khan is a PhD candidate in Electrical Engineering at the University of California Berkeley, supervised by Professor Sayeef Salahuddin and co-advised by Professor Ramamoorthy Ramesh and Professor Chenming Hu. His research interests lie in novel nanoelectronic devices and emerging frontiers in computing by leveraging advanced multifunctional materials such as complex oxides, ferroelectrics/multiferroics, and by combining high quality materials growth, innovative integration, fabrication, and characterization techniques. The work led by him resulted in the first experimental proof-of-concept demonstration of ferroelectric negative capacitance, a novel physical effect proposed in 2008 that could help to beat the "Boltzmann Limit" of 60 mV/dec subthreshold swing in field-effect transistors. His work also led to the first demonstration of a new type of ferroelastic 90° domain wall motion in archetypal ferroelectric thin films, which ensues without a concurrent ferroelectric 180° switching.
Prior to Berkeley, Asif received his BS in Electrical & Electronic Engineering from Bangladesh University of Engineering & Technology (BUET) in 2007. Asif was awarded the Qualcomm Innovation Fellowship in 2012, the Silver prize at the 5th TSMC Outstanding Student Research Award in 2011, the University Gold medal from BUET conferred by the Hon'ble President of Bangladesh in 2011, Bangladesh Delegation Responsibility at the Physics Nobel Laureate Meeting at Lindau in 2008, the 1st prize in IEEE R-10 Student Paper Contest in 2006, and the 2nd prize in the IEEE History Student Paper Contest in 2004.