A5047972667- Advanced Condensed Matter Physics
- 2D Materials and Applications
- Electronic and Structural Properties of Oxides
- Magnetic and transport properties of perovskites and related materials
- Physics of Superconductivity and Magnetism
- Iron-based superconductors research
- Multiferroics and related materials
- Chalcogenide Semiconductor Thin Films
- Copper-based nanomaterials and applications
- Magnetic properties of thin films
- Surface and Thin Film Phenomena
- Perovskite Materials and Applications
- Magnesium Oxide Properties and Applications
- Quantum Dots Synthesis And Properties
- MXene and MAX Phase Materials
- Atomic and Subatomic Physics Research
- Advanced Chemical Physics Studies
- ZnO doping and properties
- Heusler alloys: electronic and magnetic properties
- Geophysics and Sensor Technology
- Pigment Synthesis and Properties
University of St Andrews
2020-2024
Freie Universität Berlin
2021
We report the evolution of electronic structure at surface layered perovskite Sr_{2}RuO_{4} under large in-plane uniaxial compression, leading to anisotropic B_{1g} strains ϵ_{xx}-ϵ_{yy}=-0.9±0.1%. From angle-resolved photoemission, we show how this drives a sequence Lifshitz transitions, reshaping low-energy and rich spectrum van Hove singularities that layer hosts. comparison tight-binding modeling, find strain is accommodated predominantly by bond-length changes rather than modifications...
Abstract Van Hove singularities (VHss) in the vicinity of Fermi energy often play a dramatic role physics strongly correlated electron materials. The divergence density states generated by VHss can trigger emergence phases such as superconductivity, ferromagnetism, metamagnetism, and wave orders. A detailed understanding electronic structure these is therefore essential for an accurate description instabilities. Here, we study low-energy trilayer strontium ruthenate Sr 4 Ru 3 O 10 ,...
The metallic delafossites host ultra-high mobility carriers in the bulk, while at their polar surfaces, intrinsic electronic reconstructions stabilise markedly distinct phases, from charge-disproportionated insulators, to Rashba-split heavy-hole gases and ferromagnetic metals. understanding of these phases has been strongly informed by surface spectroscopic measurements, but previous studies have complicated presence spatially varying terminations material surface. Here, we demonstrate...
Our studies evidence an anisotropic magnetic order below $T_N = 32$~K. Susceptibility data in small fields of about 1~T reveal antiferromagnetic (AFM) for $H \perp c$, whereas \parallel c$ the are reminiscent a field-induced ferromagnetic (FM) structure. At low temperatures and field-dependent magnetization AC susceptibility metamagnetic transition at $H^+ 5$~T, which is absent c$. We assign this to from planar cycloidal spin structure fan-like arrangement above $H^+$. A fully FM polarized...
Abstract In half-metallic systems, electronic conduction is mediated by a single spin species, offering enormous potential for spintronic devices. Here, using microscopic-area angle-resolved photoemission, we show that spin-polarised two-dimensional hole gas naturally realised in the polar magnetic semiconductor AgCrSe 2 an intrinsic self-doping at its CrSe -terminated surface. Through comparison with first-principles calculations, unveil striking role of spin-orbit coupling surface gas,...
Doping of a Mott insulator gives rise to wide variety exotic emergent states, from high-temperature superconductivity charge, spin, and orbital orders. The physics underpinning their evolution is, however, poorly understood. A major challenge is the chemical complexity associated with traditional routes doping. Here, we study insulating CrO
Abstract We study the 2 × charge density wave (CDW) in epitaxially-grown monolayer TiSe . Our temperature-dependent angle-resolved photoemission spectroscopy measurements indicate a strong-coupling instability, but reveal how not all states couple equally to symmetry-breaking distortion, with an electron pocket persisting low temperature as non-bonding state. further show CDW order can be suppressed by modest doping of around 0.06(2) electrons per Ti. results provide opportunity for...
This work establishes the spectroscopic fingerprints of ferrimagnetic Mn${}_{3}$Si${}_{2}$Te${}_{6}$, providing a comprehensive understanding electronic states underpinning its magnetic interactions. The authors show pivotal role played by covalency, which weakens correlations and influences frustrations anisotropic exchange, leading to onset long-range order in this compound. approach combining experiments with state-of-the-art first-principles theory will have widespread applicability...
Closing the band gap of a semiconductor into semimetallic state gives powerful potential route to tune electronic energy gains that drive collective phases like charge density waves (CDWs) and excitonic insulator states. We explore this approach for controversial CDW material monolayer (ML) TiSe
The addition of metal intercalants into the van der Waals gaps transition dichalcogenides has shown great promise as a method for controlling their functional properties. For example, chiral helimagnetic states, current-induced magnetization switching, and giant valley-Zeeman effect have all been demonstrated, generating significant renewed interest in this materials family. Here, we present combined photoemission density-functional theory study three such compounds: , to investigate...
Terbium and gadolinium have eight seven 4$f$ electrons, respectively. This one-electron difference sparks surprisingly different behaviors. Here, the authors use spin-, angle-, energy-dependent photoemission to investigate relaxations of photo-hole in surface states terbium metal. They find distinct, spin-dependent linewidths for gadolinium, contrast spin-independent relaxation terbium. peculiar is explained by strong magnon-phonon interaction leading magnon polarons that couple both...
Mn$_3$Si$_2$Te$_6$ is a rare example of layered ferrimagnet. It has recently been shown to host colossal angular magnetoresistance as the spin orientation rotated from in- out-of-plane direction, proposed be underpinned by topological nodal-line degeneracy in its electronic structure. Nonetheless, origins ferrimagnetic structure remain controversial, while experimental structure, and role correlations shaping this, are little explored date. Here, we combine x-ray photoemission-based...
Van Hove singularities (VHss) in the vicinity of Fermi energy often play a dramatic role physics strongly correlated electron materials. The divergence density states generated by VHss can trigger emergence new phases such as superconductivity, ferromagnetism, metamagnetism, and wave orders. A detailed understanding electronic structure these is therefore essential for an accurate description instabilities. Here, we study low-energy trilayer strontium ruthenate Sr$_4$Ru$_3$O$_{10}$,...
Charge carrier doping of a Mott insulator is known to give rise wide variety exotic emergent states, from high-temperature superconductivity various charge, spin, and orbital orders. The physics underpinning their evolution is, however, poorly understood. A major challenge the chemical complexity associated with traditional routes addition or removal carriers. Here, we study insulating CrO$_2$ layer delafossite oxide PdCrO$_2$, where an intrinsic polar catastrophe provides clean route induce...