Preface

Abstract

Proceedings of the 15th International Conference on Muon Spin Relaxation, Rotation and Resonance28th August to 2nd September 2022 Parma, ItalyEditors: Giacomo Prando and Francis PrattThe 15th International Conference on Muon Spin Rotation, Relaxation and Resonance, µSR2020, took place at the University of Parma, Italy, from August 28th to September 2nd 2022, after a delay of over two years due to the COVID-19 pandemic. µSR2020 was promoted by the International Society for µSR Spectroscopy (ISMS) and co-organised by the Department of Mathematical, Physical and Computer Sciences of the University of Parma in Italy and the ISIS Muon Group at the STFC Rutherford Appleton Laboratory in the UK.µSR spectroscopy makes use of beams of positive and negative muons that are produced at only a small (but growing) number of accelerator facilities around the world. This conference series, which started in 1978 in Rorschach, Switzerland, and has continued with a triennial cadence until the present day, plays a very important role in fostering the exchanges of a well-established, open community of users, promoting and disseminating new experimental developments, as well as informing on scientific breakthroughs associated with the technique and the theoretical advances that support data interpretation.After the uncertainties of the pandemic years, the organisers welcomed the strong support shown by the community for the meeting, with 183 delegates from 17 different countries attending this 15th edition. Of these, it was good to see over 40 early stage researchers taking part in the conference. At the time of the meeting, delegates from a number of countries were still finding international travel difficult, and therefore hybrid sessions were included in the programme to allow remote participation.The Conference Program was selected with the generous help of an International Advisory Committee of 32 distinguished scientists, chaired by Mauro Riccò, University of Parma, and a Scientific Program Committee, composed of nine distinguished scientists, chaired by Pietro Carretta, University of Pavia. Outreach to the local community was an important aspect of the Conference, which was enhanced by a well-attended public engagement event held on the Thursday evening at the Museo APE Parma.Following a well-established tradition, the conference opened with a Student Day on the Sunday. Starting with a short session of four introductory tutorials, the bulk of the day was given over to the students themselves, to share their research with their peers though 12 selected contributions. The day was very well attended (with up to 70 delegates taking part), with the new format much appreciated by all.The start of the regular event was marked by the award of the Yamazaki Prize to Stephen Blundell, followed by his Yamazaki Prize Lecture on ‘The Quantum Muon’. The program was built around eight plenary keynote talks, covering a diverse range of subjects in condensed matter, materials and molecular sciences, where muon spectroscopy is making a significant contribution. Continuing a tradition started at a previous meeting, these contributions were selected from distinguished scientists who, while friends of µSR, are mostly active in complementary fields. The keynote talks were given by Catia Arbizzani (Bologna, energy materials), Bruce Gaulin (McMaster, spin liquids), Giacomo Ghiringhelli (Milano, strongly correlated electron systems), Reizo Kato (RIKEN, molecular materials), Ioan Pop (Karlsruhe, superconducting quantum circuits), Jorge Quintanilla (Kent, machine learning to analyse muon results), Roberta Sessoli (Florence, single molecule magnets) and Reiner Zorn (Jülich, dynamics of liquids, glasses and polymers).The 49 oral contributions presented during the conference were selected from the submitted abstracts. While many of these were related to the topics of the keynote talks, others extended the discussion to applications of muons in additional areas. Presentations were grouped into sessions covering topical subject areas such as Spin Liquids (seven), Strongly Correlated Electron systems (six), Superconductivity (eight), Energy Materials (five), Semiconductors (five), Molecular Chemistry (six), Site Calculations (five) and New Techniques (three). The conference also introduced a session on Muonic x-rays, with the four presentations covering areas such as cultural heritage and in-operando batteries. A further session was dedicated to six facility reports, testifying to the active developments going on at the established facilities and the progress of future ones. Three poster sessions accommodated 129 further contributions across a similar range of subjects, with an online forum catering for those who could not join us at the meeting. The ISMS awarded two prizes to young scientists for best oral and poster presentations, with three further poster prizes awarded to young scientists by the Conference. The meeting concluded with a Conference Summary talk by Tom Lancaster and a closing ceremony, the latter being led by the Conference Honorary Chair, Cesare Bucci.List of Conference Organisation and Sponsor lists and the confererence photograph are available in the pdf.