Spectrum of Andreev Bound States in a Molecule Embedded Inside a Microwave-Excited Superconducting Junction

Non-dissipative Josephson current through nanoscale superconducting constrictions is carried by spectroscopically sharp energy states, so-called Andreev bound states. Although theoretically predicted almost 40 years ago, no direct spectroscopic evidence of these Andreev bound states exists to date. We propose a novel type of spectroscopy based on embedding a superconducting constriction, formed by a single-level molecule junction, in a microwave QED cavity environment. In the electron-dressed cavity spectrum we find a polariton excitation at twice the Andreev bound state energy, and a superconducting-phase dependent ac Stark shift of the cavity frequency. Dispersive measurement of this frequency shift can be used for Andreev bound state spectroscopy.Comment: Published version; 4+ pages, 3 figure

Transport Through Andreev Bound States in a Graphene Quantum Dot

Andreev reflection-where an electron in a normal metal backscatters off a superconductor into a hole-forms the basis of low energy transport through superconducting junctions. Andreev reflection in confined regions gives rise to discrete Andreev bound states (ABS), which can carry a supercurrent and have recently been proposed as the basis of qubits [1-3]. Although signatures of Andreev reflection and bound states in conductance have been widely reported [4], it has been difficult to directly probe individual ABS. Here, we report transport measurements of sharp, gate-tunable ABS formed in a superconductor-quantum dot (QD)-normal system, which incorporates graphene. The QD exists in the graphene under the superconducting contact, due to a work-function mismatch [5, 6]. The ABS form when the discrete QD levels are proximity coupled to the superconducting contact. Due to the low density of states of graphene and the sensitivity of the QD levels to an applied gate voltage, the ABS spectra are narrow, can be tuned to zero energy via gate voltage, and show a striking pattern in transport measurements.Comment: 25 Pages, included SO

Design thinking and design doing: Describing a process of people-centred innovation

The research forms part of the author’s long-term enquiry into the challenges of implementing Design Thinking (DT) and its relationship to Inclusive Design (ID), something that has been understudied and under-researched. Both fields advocate research with users and have a history spanning decades, but they have remained largely separate in terms of academic research and practical application. The author was approached by the series editor for his expertise at the intersection of ID and DT. “State of the art” DT ideas and approaches were evaluated through study of circa 50 recent academic publications, papers and journal articles. Field research was based on personal leadership of over 70 ID projects with government, business, and the voluntary sector leading to frontline discoveries and insights. Peer-reviewed academic publication, conference presentation, and keynote delivery helped test ideas before making the link between ID and DT and delivering the publication. This 13,000 word, sole-authored chapter outlines gaps in the long-term effectiveness of DT, outlining five principles that aim to engender a more sustainable approach by aligning it to ID. These five ideas give an overview of newly-articulated frameworks, tools and methods for academic and industry application. The chapter sets a context for 16 other chapters within the publication and establishes the need for more empirical research to link between DT and ID. The ideas in the chapter have been used to direct practice-based research projects and education programmes at the RCA as well as organisations in its network. 700 Hong Kong civil servants have been trained using these ideas, alongside numerous industry organisations including Tata Consulting Services and Panasonic

Mortality risk increased in colonic diverticular disease : a nationwide cohort study

Introduction: There are limited population cohort data on overall and cause-specific mortality in colonic diverticular disease.Objective: To measure overall and cause-specific mortality in colonic diverticular disease, compared to matched reference individuals and siblings.Methods: Population-based cohort study ("the ESPRESSO study") in Sweden. There were 97,850 cases with a medical diagnosis of diverticular disease (defined by international classification of disease codes) and colorectal histology identified in 1987-2017 from histopathology reports. The mortality risk between individuals with colonic diverticular disease and matched reference individuals ( n = 453/634) from the general population was determined. Cox regression models adjusted for comorbidity estimated hazard ratios (HRs) for all-cause mortality