A quantum bit is qualitatively different from a classical bit as it allows for the coherent super-position of possibilities, which demonstrate different behaviours depending on the phase between them. These behaviours constitute as interference phenomena, and lie behind the existence of algorithms in quantum computing which are arguably faster than the best classical alternatives.
What if quantum theory did not hold in all scenarios, or was only a limiting case of some broader theory? In this case, can we still meaningfully talk about phase and interference? In this talk, I will present key results from a project to generalize phase and interference into post-quantum theories. I will discuss the special role the uncertainty principle plays in enabling non-trivial dynamics, and draw conclusions about the possibility of non-classical algorithms for computation beyond quantum theory.
Andrew Garner is a quantum information theorist, who completed his DPhil at the University of Oxford, and is now a Research Fellow at the Centre for Quantum Technologies at the National University of Singapore. His has made notable contributions to the foundations of quantum theory, where he has pioneered a framework to extend phase beyond quantum theory. He is also interested in quantum thermodynamics and single-shot statistical mechanics.