Assembling bosonic quantum computers
Dr. Hoi-Kwan (Kero) Lau, University of Chicago
Leuchs-Russell Auditorium, A.1.500, Staudtstr. 2
With the (controversial) demonstration of “quantum supremacy”, quantum computing has lately captured the news headlines. While the recent development is exciting, the current qubit-type quantum computers are still suffering from limitations in, e.g. scalability, information capacity, and coherence time. On the other hand, there are ubiquitous quantum systems that behave as bosons (harmonic oscillators), and some demonstrated superior properties that might provide alternative solutions to the qubit problems.
In this talk, I will briefly discuss our recent progresses in improving various bosonic components of quantum computers. For the processor, we found a universal interaction that can implement logic gates regardless of how the information is represented by a bosonic wavefunction. Such powerful interaction is also a crucial component in implementing quantum machine learning, and can surprisingly allow quantum computation with highly thermalized oscillators. For data transmission, we studied the optomechanical transducer that interconverts microwave and optical signals. While sideband-resolved cavity was once believed necessary, we developed a strategy that permits high fidelity transduction even though the cavity is unresolved. For memory transfer, we studied the most general interface between a system and a memory mode. Although such interface is practically limited by the details of coupling, we showed that a perfect transfer can always be realized with any two applications of imperfect interfaces. We believe assembling these components could be a promising route to bring advantageous quantum computing closer to reality.