Monash Quantum Information Science

Quantum dynamics

A central obstacle in predicting the future states of a dynamical system is to understand how much of the system's past affects its future. This topic is crucial for understanding the necessary resources to model the dynamics of an arbitrary system. We are working to operationally characterise non-Markovian dynamics. The methods we develop will be used to battle non-Markovian noise via new error correction methods.

Probing complex systems

We are developing new methods to probe complex quantum systems using simple probes. By using techniques from open quantum systems theory, we recently showed that a two-level probe (the simplest kind of quantum system) can determine the full energetic structure of a complex system, such as a large molecule, with no prior knowledge of the system. This new form of spectroscopy is highly general and could be applied to many interesting experimental systems.

Quantum thermodynamics

We are working to understand how work, heat, and power function at the mesoscopic level. Recently we have shown that quantum batteries can be charged faster than what is classically possible. We have also developed a fluctuation-like relationship for heat for a Landauer erasure procedure. Finally, we have devised an interferometric method to measure heat at the quantum level, which has been used measure heat dissipation in quantum process on two qubits.

Quantum correlations in quantum technologies

We study noisy quantum correlations and their advantage over classical correlations in different models of computation, communication, and metrology. This is an exciting and growing field that aims to understand the differences between the quantum and classical worlds, using the tools of information theory, computation, thermodynamics, and many-body physics. In specific, we have shown quantum advantage in metrology that is independent of entanglement.

Bell correlations and information causality

Entanglement, no-signalling, Bell's inequality violation; these are all properties of quantum physics that are absent in classical physics. However, they are not unique properties in a larger class of theories called non-signalling theories, of which quantum physics is part of. Then, what physical principles elevate quantum physics from mathematics to an actual description of our world? In 2009 the principle of information causality was put forth to, in part, differentiate quantum physics from other non-signalling theories. This principle was formulated in a primarily spatial setting–we apply this concept to the temporal setting and consider the effects of different quantum channels, and Markovian and non-Markovian scenarios.