Bridging the quantum-classical divide

In this theme we will seek to better understand the quantum-classical (QC) interface and the irreversible behaviour that originates there. We will blend geometric mechanics and stochastic methods with physical intuition to provide new solutions to questions in QC dynamics and the origin of decoherence and irreversibility, along with its thermodynamic direction of time.

Specifically, we will combine our new developments on the mathematics of Koopman wave functions with our constructor theory to provide an entirely new framework for the description of hybrid QC systems.

Research aims

Our research will focus on three strands of investigation:

Developing a reversible theory of QC coupling to overcome known consistency issues
Considering entropy sources for describing irreversibility
Investigating the emergence of classicality in dynamic models.

The development of QC theories and the inclusion of environmental entropy sources will require us to revisit several concepts which have long been discussed but which have lacked a mathematical perspective to enable realistic quantitative predictions. This aspect will be particularly relevant for the development of new methods in molecular dynamics.

References

Bhole, G; Jones, J.A.; Marletto, C.; Vedral, V., Witnesses of non-classicality for simulated hybrid quantum systems, J. Phys. Comm. 4 025013 (2020)
D.I. Bondar, F. Gay-Balmaz, C. Tronci, Koopman wavefunctions and classical–quantum correlation dynamics, Proc. R. Soc. Lond. Ser. A 475 (2019), 20180879
Deutsch, D.; Marletto, C., Constructor theory of information, Proc. Royal Soc. A 471 (2015).
F. Gay-Balmaz, C. Tronci, Madelung transform and probability densities in hybrid classical-quantum dynamics, Nonlinearity 33 (2020), n. 10, 5383