Research

Understanding the difference between the “quantum” and the “classical” in a mathematically rigorous way has been the leitmotif of my work in quantum foundations. The approach I have adopted in pursuing this agenda is an information-theoretic one, largely drawing on the perspective of quantum information theory.

An explosion of current research in quantum foundations has meant that research on different foundational aspects of quantum theory takes a while to cross-fertilize. On the other hand, the parallel proliferation research in quantum information and computation doesn’t incorporate developments in quantum foundations to its advantage soon enough. My research is therefore guided by the twin principles of ensuring

  • a productive exchange between research on different foundational aspects of quantum theory, and
  • an ongoing cross-fertilization of ideas at the interface of quantum foundations (and the questions it motivates) and quantum practice, whether it’s in physics, information, or computation.

My current research interests include:

Contextuality, the fact that it is impossible to make sense of operational quantum theory in terms of a picture of reality that satisfies the Leibnizian idea of the identity of indiscernibles. References: my PhD thesis, introductory papers by Rob Spekkens.

Joint measurability or, rather, the fact that measurements in quantum theory can fail to be jointly implementable, i.e., the incompatibility of observables. References: a recent introductory article by Teiko Heinosaari.

Resource theories of nonclassicality, which consider the problem of how to characterize the resourcefulness of nonclassical properties that are considered useful in quantum information, e.g., entanglement, incompatibility, Bell nonlocality, contextuality. References: the Coecke-Fritz-Spekkens framework, a recent article on quantifying entanglement in Bell scenarios via local operations and shared randomness (LOSR) rather than local operations and classical communication (LOCC).

Causality, i.e., the nature of causal relationships in a quantum world and how that differs from classical causality, and what this might mean for attempts at reconciling quantum theory and general relativity. References: an overview here, the recent quantum causal models framework, an essay by Rob Spekkens, and an interview with Lucien Hardy.

Axiomatic foundations of quantum theory, i.e., the reduction of quantum theory to a minimal set of logically independent assumptions in the hopes of understanding which features of the theory make it go and how they play with each other. References: this book.