At the core of Quantum Information Science (QIS) is the idea that information processing is limited by the laws of physics that the carrier of information must obey. Most of today’s information is encoded in a classical way, as the on/off of voltage in an electrical circuit for instance, or the point depth engraved on a CD. However, it is conceivable and increasingly realistic to encode information on genuinely quantum objects. For example the polarisation of a single photon, horizontal or vertical, is a way to encode a bit. The point of this is that quantum physics adds a new dimension to processing logic. The ability to bring a quantum object in two states at the same time, in superposition, was made famous by Schrödinger with his cat. Exactly this superposition can be used to perform a new kind of “coherent” information processing that results in the exponential power increase of a quantum computer over the classical one. Moreover, quantum objects can share correlations much stronger than their classical counterpart. This “spooky action” (Einstein) is known as quantum entanglement.

Part of our research is to clarify the role of entanglement in quantum computing. Specifically, we found that the computing power of correlations can be characterised using a novel framework. The framework describes how an external control computer can, by interacting with quantum correlated resource states, perform calculations beyond its own power. We also introduced a new programmable version for building a quantum computer. Ideally suited for experiments, Ancilla-Driven Quantum Computation (ADQC) requires only a single moving quantum system, the ancilla, and a single interaction.

An increasing part of our research is devoted to thermodynamics in the quantum regime, and the links between information theory and thermodynamics. We confirmed that while quantum entanglement is known to enable many counterintuitive effects, entanglement is not able to violate the second law of thermodynamics. However, entanglement is not just a low temperature effect. In the right environment it can persist at high temperatures and even exists in biological systems, for instance, between the electronic clouds of DNA base pairs.

Currently we are working on characterising the behaviour of quantum systems in non-equilibrium. We are also involved in an experiment with a tiny nanosphere.