Controllable magnetism and an anomalous Hall effect in (Bi1−xSbx)2Te3-intercalated MnBi2Te4 multilayers

Nanoscale Royal Society of Chemistry (2025)

Authors:

Peng Chen, Jieyi Liu, Yifan Zhang, Puyang Huang, Jack Bollard, Yiheng Yang, Ethan L Arnold, Xinqi Liu, Qi Yao, Fadi Choueikani, Gerrit van der Laan, Thorsten Hesjedal, Xufeng Kou

Abstract:

MnBi2Te4-based superlattices not only enrich the materials family of magnetic topological insulators, but also offer a platform for tailoring magnetic properties and interlayer magnetic coupling through the strategic insertion layer design. Here, we present the electrical and magnetic characterization of (Bi1-xSbx)2Te3-intercalated MnBi2Te4 multilayers grown by molecular beam epitaxy. By precisely adjusting the Sb-to-Bi ratio in the spacer layer, the magneto-transport response is modulated, unveiling the critical role of Fermi level tuning in optimizing the anomalous Hall signal and reconfiguring the magnetic ground state. Moreover, by varying the interlayer thickness, tunable magnetic coupling is achieved, enabling precise control over ferromagnetic and antiferromagnetic components. These findings pave the way for the exploration of versatile magnetic topological phases in quantum materials systems.

Photo-induced chirality in a nonchiral crystal

Science American Association for the Advancement of Science 387:6732 (2025) 431-436

Authors:

Z Zeng, M Först, M Fechner, M Buzzi, Eb Amuah, C Putzke, Pjw Moll, D Prabhakaran, Pg Radaelli, A Cavalleri

Abstract:

Chirality, a pervasive form of symmetry, is intimately connected to the physical properties of solids, as well as the chemical and biological activity of molecular systems. However, inducing chirality in a nonchiral material is challenging because this requires that all mirrors and all roto-inversions be simultaneously broken. Here, we show that chirality of either handedness can be induced in the nonchiral piezoelectric material boron phosphate (BPO4) by irradiation with terahertz pulses. Resonant excitation of either one of two orthogonal, degenerate vibrational modes determines the sign of the induced chiral order parameter. The optical activity of the photo-induced phases is comparable to the static value of prototypical chiral α-quartz. Our findings offer new prospects for the control of out-of-equilibrium quantum phenomena in complex materials.

Momentum-dependent electron-phonon coupling in cuprates by RIXS: the roles of phonon symmetry and electronic structure

(2025)

Authors:

Maryia Zinouyeva, Rolf Heid, Giacomo Merzoni, Riccardo Arpaia, Nikolai Andreev, Marco Biagi, Nicholas B Brookes, Daniele Di Castro, Alexei Kalaboukhov, Kurt Kummer, Floriana Lombardi, Leonardo Martinelli, Francesco Rosa, Flora Yakhou-Harris, Lucio Braicovich, Marco Moretti Sala, Paolo G Radaelli, Giacomo Ghiringhelli

Colour symmetry and non-collinear altermagnetism

(2025)

Authors:

Paolo G Radaelli, Gautam Gurung

Tensorial approach to altermagnetism

Physical Review B American Physical Society (APS) 110:21 (2024) 214428