arXiv subjects

S. N. A. Duffus

Publications and source records attributed to S. N. A. Duffus.

3 recordsLinked to original sources

arXiv2026

Systemically Designed Degrees for Real-World Challenges: A case study on Physics curriculum design at Loughborough University

We present a ground-up redesign of the undergraduate physics degree at Loughborough University, driven by the principle of authenticity in academic and industrial practice. Departing from conventional incremental reforms, we adopt a systems-engineering approach to programme-level curriculum design, treating the degree as an integrated system with verifiable performance. This methodology aligns stakeholder-derived requirements with vertically-integrated threads in theory, computation, laboratory practice, and professional skills. We demonstrate that this approach enables students to achieve levels of disciplinary and cross-disciplinary competence beyond those typically expected at undergraduate level. Outcomes are supported by graduate destinations, enhanced student performance, and positive external evaluations, including national accreditation. Our results suggest that rigorous, system-level curriculum design can yield transformational gains in both capability and confidence.

physics.ed-ph↗

arXiv2017

On open quantum systems, effective Hamiltonians and device characterization

High fidelity models, which support accurate device characterization and correctly account for environmental effects, are crucial to the engineering of scalable quantum technologies. As it ensures positivity of the density matrix, one preferred model for open systems describes the dynamics with a master equation in Lindblad form. The Linblad operators are rarely derived from first principles, resulting in dynamical models which miss those additional terms that must generally be added to bring the master equation into Lindblad form, together with concomitant other terms that must be assimilated into an effective Hamiltonian. In first principles derivations such additional terms are often cancelled (countered), frequently in an ad hoc manner. In the case of a Superconducting Quantum Interference Device (SQUID) coupled to an Ohmic bath, the resulting master equation implies the environment has a significant impact on the system's energy. We discuss the prospect of keeping or cancelling this impact; and note that, for the SQUID, measuring the magnetic susceptibility under control of the capacitive coupling strength and the externally applied flux, results in experimentally measurable differences between models. If this is not done correctly, device characterization will be prone to systemic errors.

quant-ph↗

arXiv2016

Some implications of superconducting quantum interference to the application of master equations in engineering quantum technologies

In this paper we consider the modelling and simulation of open quantum systems from a device engineering perspective. We derive master equations at different levels of approximation for a Superconducting Quantum Interference Device (SQUID) ring coupled to an ohmic bath. We demonstrate that the master equations we consider produce decoherences that are qualitatively and quantitativly dependent on both the level of approximation and the ring's external flux bias. We discuss the issues raised when seeking to obtain Lindbladian dissipation and show, in this case, that the external flux (which may be considered to be a control variable in some applications) is not confined to the Hamiltonian, as often assumed in quantum control, but also appears in the Lindblad terms.

quant-ph↗