Nikos Hardavallas works on parallel systems and computer architecture, primarily on techniques to enable extreme-scale multicore processors and practical quantum systems. Such designs are elusive due to the technological limitations on yield, power and memory bandwidth of conventional systems, and the nascency of quantum and silicon-photonic technologies. His research aims to pave the way to energy-efficient computing by investigating ideas to combat dark silicon, and to speed up the execution of programs by several factors through parallelism extraction, novel architectures, blending of compilers, runtimes, operating systems and hardware, and the use of emerging technologies. More recently, his research focus is on accelerating the advent of practical quantum computing through innovation at the quantum system stack. Prof. Hardavellas' work extends across multiple computing layers: emerging devices (nanophotonics, quantum), circuit design, processor architecture, memory systems, interconnects, compilers, runtime environments, system software and parallel execution models.