Tuning a two-impurity Kondo system by a moir\'e superstructure

Two-impurity Kondo models are paradigmatic for correlated spin-fermion systems. Working with Mn atoms on Au(111) covered by a monolayer of MoS$_2$, we tune the inter-adatom exchange via the adatom distance and the adatom-substrate exchange via the location relative to a moir\'e structure of the substrate. Differential-conductance measurements on isolated adatoms exhibit Kondo peaks with heights depending on the adatom location relative to the moir\'e structure. Mn dimers spaced by a few atomic lattice sites exhibit split Kondo resonances. In contrast, adatoms in closely spaced dimers couple antiferromagnetically, resulting in a molecular-singlet ground state. Exciting the singlet-triplet transition by tunneling electrons, we find that the singlet-triplet splitting is surprisingly sensitive to the moir\'e structure. We interpret our results theoretically by relating the variations in the singlet-triplet splitting to the heights of the Kondo peaks of single adatoms, finding evidence for coupling of the adatom spin to multiple conduction electron channels

Psychometric properties of the Worker Role Interview (version 10.0) in mental health

Introduction: Occupational therapists working in psychiatry are routinely required to undertake vocational assessments and to support clients into work. To make such efforts successful, the use of evidence-based practice and outcome measures is becoming increasingly important. Objectives: The objectives were to examine the psychometric properties of the Worker Role Interview (WRI, version 10.0) with a psychiatric population in the United Kingdom, particularly its construct validity as a baseline assessment and an outcome measure. Method: Data were collected from 34 psychiatric clients rated by seven occupational therapists. Rasch analysis was used to examine scale validity, validity of therapists' rating patterns of clients, rater consistency, precision of client measurement and the scale's aptitude in detecting different ability levels. Results: All items except one demonstrated acceptable goodness-of-fit to the Rasch model. Over 90% of clients fitted the model. The scale detected five ability levels, but client measures were slightly imprecise. Raters used the scale consistently and implications of rater leniency are discussed. Conclusion: The study provides evidence of construct validity, supporting the use of the WRI as a standardised baseline assessment in a mental health population. Further development of the WRI might be indicated and its usefulness as an outcome measure should be tested with larger samples. The College of Occupational Therapists Ltd.sch_occ75pub2760pub

Synthesis of a single cycle of light with compact erbium-doped fibre technology

The advent of self-referenced optical frequency combs1, 2 has sparked the development of novel areas in ultrafast sciences such as attosecond technology3, 4 and the synthesis of arbitrary optical waveforms5, 6. Few-cycle light pulses are key to these time-domain applications, driving a quest for reliable, stable and cost-efficient mode-locked laser sources with ultrahigh spectral bandwidth. Here, we present a set-up based entirely on compact erbium-doped fibre technology, which produces single cycles of light. The pulse duration of 4.3 fs is close to the shortest possible value for a data bit of information transmitted in the near-infrared regime. These results demonstrate that fundamental limits for optical telecommunications are accessible with existing fibre technology and standard free-space components