peterwahl

How does the quasiparticle interference (QPI) of moiré-induced flat bands look like? Read Bruno’s preprint (https://arxiv.org/abs/2511.05648) about a new route to stabilise flat bands in emergent moiré periodicities, and how the flat bands look like in ARPES and QPI. Not only do we show QPI of the flat bands, but the manuscript introduces a new way to stabilise functional moiré heterostructures by exploiting CDW periodicities. Great collaboration with the group of Phil King and the Centre for Designer Quantum Materials (https://www.cdqm.uk/).

How can one use real space imaging to obtain k-space information of the electronic states in a material? Our preprint on quasiparticle interference imaging of strongly correlated and 2D materials summarises the state of the art in theory and experiment and is an attempt at a comprehensive review. Great collaboration across continents, with contributions from Luke Rhodes, Yuhki Kohsaka, Tetsuo Hanaguri, and Carolina Marques.

Congratulations to Daniel Halliday for his PhD thesis on “Surface structure of the ruthenium oxides: correlating atomic displacements with electronic structure” and graduation earlier this month!

Condensed matter retreat at the Burn in Glenesk with lots of physics, some football and exciting discussions.

If you are interested in physics and art, come to see the exhibition Quantum Dialogues at the Byre Theatre – with exhibits on display 9th June until 31st July. Below ‘Superposition’ by Ru Christman with Siri Berge encapsulating the essence of real and momentum space, lattices, defects and the magic hiding behind atomic scale images obtained by quantum tunneling.

Ru (left) and Siri behind ‘Superposition’. If you are interested in this or other artworks by Ru Christman, see here.

It’s that time of year again – looking forward to our annual condensed matter retreat at the Burn in Glenesk and to an exciting programme and discussions. For more information see the dedicated webpage.

Submit an abstract by the (extended) submission deadline on 3 May for minicolloquia 02 and 06 at the CMD in Graz, with an exciting programme of invited speakers. Supported by ICAM-I2CAM, with limited funding available for travel bursaries for early career researchers.

Meet members of the group at the DPG spring meeting in Dresden. Work of the group and its members features in the following contributions:

• Siri A. Berge in TT5.10: “Atomic scale imaging of the effect of chemical pressure in Sr_2−xBa_xRuO₄“, Mon 12pm, room CHE/0089.
• Rebecca Bisset in TT29.2: “Determining the superconducting order parameter of UPt₃ using scanning tunneling microscopy”, Tue 9.45am, room CHE/0091.
• Carolina A. Marques in O80.3 (Gerhard Ertl Young Investigator Award Competition): “Exchange-driven magnetoelastic coupling in a correlated itinerant ferromagnet”, Thu 11:30am, room TRE/PHYS.
• Uladzislau Mikhailau in O93.5: “Imaging stripe dynamics in superconducting nickelate “, Fri 10:30am, room HSZ/0201.
• Peter Wahl in O93.7: “calcQPI – a tool to simulate quasiparticle interference”, Fri 11:00am, room HSZ/0201.

Look for a PhD position? Apply for a PhD project in the stimulating environment of the Centre for Designer Quantum Materials, working on experimental physics, instrument development or numerical modelling.

You can find example projects here, a few projects for which we specifically are looking for candidates this year are listed here:

• joint Bonn-St Andrews St Leonhard scholarship: Combining Correlation and Non-Equilibrium Effects with Band Structure in Strongly Correlated Quantum Materials, Probed by Quasiparticle Interference (co-supervised with Prof Hans Kroha, University of Bonn). Application deadline: 27 February 2026.

Submit applications here.

Need some Christmas reading?🎄 How about our new preprint where we show how Andreev bound state spectroscopy can be used to determine the symmetry of the order parameter in the case of UPt₃. Turns out, it’s important that there is spin-orbit coupling.

Spoiler alert: looks like singlet pairing with E_1g symmetry is most consistent with our data.

Read the full preprint at:

• Rebecca Bisset, Luke C. Rhodes, Hugo Decitre, Matthew J. Neat, Ana Maldonado, Andrew Huxley, Carolina A. Marques, and Peter Wahl, Determining the superconducting order parameter of UPt₃ using scanning tunneling microscopy, arxiv/2512.15845.