Quantum computing is on the horizon. Already prototype machines exist and there is an increasing global push to realise the full potential of quantum enhanced devices. The advantages associated with quantum computing, principally the exponential speed-up of certain tasks, have been explored over the last 30 years and this is reflected in the development of several different models for quantum computation: “gate-based” where quantum logic gates similar to today's AND/OR gates perform the computation, “measurement-based” where a highly entangled initial state is prepared and then through a sequence of measurements a computation is performed, and “adiabatic” approaches where a given problem is encoded into a quantum model where the ground state corresponds to the solution. While these models differ significantly in their implementation, they nevertheless are all are universal models for quantum information processing, meaning that they can perform any computation. A significant road block to commercially viable quantum computers can be related to their scalability. Far be it from a mere engineering issue, the inherent fragility of quantum states means going beyond the small scale noisy prototypes available today to a useful functioning quantum computer is a highly non-trivial task. A further significant issue is the energetic resources necessary for a given experimental platform to perform a quantum algorithm. This necessitates a systematic study of the thermodynamics of quantum computational models. The aim of this project is to identify the most thermodynamically efficient model for quantum computation. By quantitatively assessing the energy requirements for the coherent control of quantum systems, and by taking into account unavoidable environmental spoiling effects.
Publications
Counterdiabatic control in the impulse regime Eoin Carolan, Anthony Kiely, and Steve Campbell Phys. Rev. A 105, 012605 (2022)
Commutativity and the emergence of classical objectivity Eoghan Ryan, Eoin Carolan, Steve Campbell, and Mauro Paternostro J. Phys. Commun. 6, 095005 (2022)
Robustness of controlled Hamiltonian approaches to unitary quantum gates Eoin Carolan, Barış Çakmak, and Steve Campbell Phys. Rev. A 108, 022423 (2023)
Operator growth and spread complexity in open quantum systems Eoin Carolan, Anthony Kiely, Steve Campbell, and Sebastian Deffner EPL 147, 38002 (2024)