Publications


Formation of Hubbard-like bands as a fingerprint of strong electron-electron interactions in FeSe

PHYSICAL REVIEW B 95 , 081106(R) (2017) (2017)

MD Watson, S Backes, AA Haghighirad, M Hoesch, TK Kim, AI Coldea, R Valenti


Temperature-induced phase transition from cycloidal to collinear antiferromagnetism in multiferroic Bi0.9Sm0.1FeO3 driven by f-d induced magnetic anisotropy

PHYSICAL REVIEW B 95 (2017) ARTN 054420

RD Johnson, PA McClarty, DD Khalyavin, P Manuel, P Svedlindh, CS Knee


Electrical Switching of Magnetic Polarity in a Multiferroic BiFeO3 Device at Room Temperature

PHYSICAL REVIEW APPLIED 8 (2017) ARTN 014033

NW Price, RD Johnson, W Saenrang, A Bombardi, FP Chmiel, CB Eom, PG Radaelli


Ultrahigh magnetic field spectroscopy reveals the band structure of the three-dimensional topological insulator Bi2Se3

PHYSICAL REVIEW B 96 (2017) ARTN 121111

A Miyata, Z Yang, A Surrente, O Drachenko, DK Maude, O Portugall, LB Duffy, T Hesjedal, P Plochocka, RJ Nicholas


Quasiparticle Breakdown and Spin Hamiltonian of the Frustrated Quantum Pyrochlore Yb_{2}Ti_{2}O_{7} in a Magnetic Field.

Physical review letters 119 (2017) 057203-

JD Thompson, PA McClarty, D Prabhakaran, I Cabrera, T Guidi, R Coldea

The frustrated pyrochlore magnet Yb_{2}Ti_{2}O_{7} has the remarkable property that it orders magnetically but has no propagating magnons over wide regions of the Brillouin zone. Here we use inelastic neutron scattering to follow how the spectrum evolves in cubic-axis magnetic fields. At high fields we observe, in addition to dispersive magnons, a two-magnon continuum, which grows in intensity upon reducing the field and overlaps with the one-magnon states at intermediate fields leading to strong renormalization of the dispersion relations, and magnon decays. Using heat capacity measurements we find that the low- and high-field regions are smoothly connected with no sharp phase transition, with the spin gap increasing monotonically in field. Through fits to an extensive data set of dispersion relations combined with magnetization measurements, we reevaluate the spin Hamiltonian, finding dominant quantum exchange terms, which we propose are responsible for the anomalously strong fluctuations and quasiparticle breakdown effects observed at low fields.


Crystal growth of pyrochlore rare-earth stannates

JOURNAL OF CRYSTAL GROWTH 468 (2017) 335-339

D Prabhakaran, S Wang, AT Boothroyd


Spectroscopic evidence for the gapless electronic structure in bulk ZrTe5

JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA 219 (2017) 45-52

L Shen, MX Wang, SC Sun, J Jiang, X Xu, T Zhang, QH Zhang, YY Lv, SH Yao, YB Chen, MH Lu, YF Chen, C Felser, BH Yan, ZK Liu, LX Yang, YL Chen


Crystal growth of the triangular-lattice antiferromagnet Ba3CoSb2O9

JOURNAL OF CRYSTAL GROWTH 468 (2017) 345-348

D Prabhakaran, AT Boothroyd


Synthesis of Superconductor-Topological Insulator Hybrid Nanoribbon Structures

NANO 12 (2017) ARTN 1750095

P Schonherr, F Zhang, V Srot, P van Aken, T Hesjedal


Direct experimental determination of the topological winding number of skyrmions in Cu2OSeO3.

Nature communications 8 (2017) 14619-

SL Zhang, G van der Laan, T Hesjedal

The mathematical concept of topology has brought about significant advantages that allow for a fundamental understanding of the underlying physics of a system. In magnetism, the topology of spin order manifests itself in the topological winding number which plays a pivotal role for the determination of the emergent properties of a system. However, the direct experimental determination of the topological winding number of a magnetically ordered system remains elusive. Here, we present a direct relationship between the topological winding number of the spin texture and the polarized resonant X-ray scattering process. This relationship provides a one-to-one correspondence between the measured scattering signal and the winding number. We demonstrate that the exact topological quantities of the skyrmion material Cu2OSeO3 can be directly experimentally determined this way. This technique has the potential to be applicable to a wide range of materials, allowing for a direct determination of their topological properties.


Temperature evolution of topological surface states in Bi2Se3 thin films studied using terahertz spectroscopy

TERAHERTZ, RF, MILLIMETER, AND SUBMILLIMETER-WAVE TECHNOLOGY AND APPLICATIONS X 10103 (2017)

VS Kamboj, A Singh, HE Beere, T Hesjedal, CHW Barnes, DA Ritchie


Lifshitz Transitions Induced by Temperature and Surface Doping in Type-II Weyl Semimetal Candidate T-d-WTe2

PHYSICA STATUS SOLIDI-RAPID RESEARCH LETTERS 11 (2017) ARTN 1700209

Q Zhang, Z Liu, Y Sun, H Yang, J Jiang, S-K Mo, Z Hussain, X Qian, L Fu, S Yao, M Lu, C Felser, B Yan, Y Chen, L Yang


Combining microscopic and macroscopic probes to untangle the single-ion anisotropy and exchange energies in an S=1 quantum antiferromagnet

PHYSICAL REVIEW B 95 (2017) ARTN 134435

J Brambleby, JL Manson, PA Goddard, MB Stone, RD Johnson, P Manuel, JA Villa, CM Brown, H Lu, S Chikara, V Zapf, SH Lapidus, R Scatena, P Macchi, Y-S Chen, L-C Wu, J Singleton


ARPES study of the epitaxially grown topological crystalline insulator SnTe(111)

JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA 219 (2017) 35-40

Y Zhang, Z Liu, B Zhou, Y Kim, L Yang, H Ryu, C Hwang, Y Chen, Z Hussain, Z-X Shen, S-K Mo


Van der Waals epitaxy between the highly lattice mismatched Cu-doped FeSe and Bi2Te3

NPG ASIA MATERIALS 9 (2017) ARTN e402

A Ghasemi, D Kepaptsoglou, PL Galindo, QM Ramasse, T Hesjedal, VK Lazarov


Emergence, causation and storytelling: Condensed matter physics and the limitations of the human mind

Philosophica 92 (2017) 139-164

SJ Blundell

The physics of matter in the condensed state is concerned with problems in which the number of constituent particles is vastly greater than can be easily comprehended. The inherent physical limitations of the human mind are fundamental and restrict the way in which we can interact with and learn about the universe. This presents challenges for developing scientific explanations that are met by emergent narratives, concepts and arguments that have a nontrivial relationship to the underlying microphysics. By examining examples within condensed matter physics, and also from cellular automata, I show how such emergent narratives efficiently describe elements of reality.


Anisotropic magnetic switching along hard [110]-type axes in Er-doped DyFe2/YFe2 thin films

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS 439 (2017) 287-293

GBG Stenning, GJ Bowden, G van der Laan, AI Figueroa, P Bencok, P Steadman, T Hesjedal


Magnetic proximity coupling to Cr-doped Sb2Te3 thin films

PHYSICAL REVIEW B 95 (2017) ARTN 224422

LB Duffy, AI Figueroa, L Gladczuk, N-J Steinke, K Kummer, G van der Laan, T Hesjedal


Topological origin of the type-II Dirac fermions in PtSe2

PHYSICAL REVIEW MATERIALS 1 (2017) ARTN 074202

Y Li, Y Xia, SA Ekahana, N Kumar, J Jiang, L Yang, C Chen, C Liu, B Yan, C Felser, G Li, Z Liu, Y Chen


Strain and Magnetic Field Induced Spin-Structure Transitions in Multiferroic BiFeO3

ADVANCED MATERIALS 29 (2017) UNSP 1602327

A Agbelele, D Sando, C Toulouse, C Paillard, RD Johnson, R Ruffer, AF Popkov, C Carretero, P Rovillain, J-M Le Breton, B Dkhil, M Cazayous, Y Gallais, M-A Measson, A Sacuto, P Manuel, AK Zvezdin, A Barthelemy, J Juraszek, M Bibes

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