A5071692047- Advanced Condensed Matter Physics
- Physics of Superconductivity and Magnetism
- Topological Materials and Phenomena
- Iron-based superconductors research
- Magnetic and transport properties of perovskites and related materials
- Rare-earth and actinide compounds
- Quantum, superfluid, helium dynamics
- Quantum many-body systems
- Graphene research and applications
- Cold Atom Physics and Bose-Einstein Condensates
- Quantum and electron transport phenomena
- 2D Materials and Applications
- Neural Networks and Applications
- Electronic and Structural Properties of Oxides
- Machine Learning in Materials Science
- Quantum Information and Cryptography
- Magnetic properties of thin films
- High-pressure geophysics and materials
- Advanced Chemical Physics Studies
- Image Processing and 3D Reconstruction
- Corporate Taxation and Avoidance
- Transition Metal Oxide Nanomaterials
- X-ray Diffraction in Crystallography
- Seismic Imaging and Inversion Techniques
- Intellectual Capital and Performance Analysis
University of Zurich
2018-2025
Micron (United States)
2014-2024
ETH Zurich
2009-2020
Weizmann Institute of Science
2014-2017
Cornell University
2011-2016
Ultrasonic Technologies (United States)
2011-2013
Veterans of Foreign Wars
2011
Instituto de Física Teórica
2009
RWTH Aachen University
1996-2006
University of Tübingen
2000
We experimentally observe many-body localization of interacting fermions in a one-dimensional quasi-random optical lattice. identify the transition through relaxation dynamics an initially-prepared charge density wave. For sufficiently weak disorder time evolution appears ergodic and thermalizing, erasing all remnants initial order. In contrast, above critical strength significant portion ordering persists, thereby serving as effective order parameter for localization. The stationary wave...
In the presence of disorder, an interacting closed quantum system can undergo many-body localization (MBL) and fail to thermalize. However, over long times even weak couplings any thermal environment will necessarily thermalize erase all signatures MBL. This presents a challenge for experimental investigations MBL, since no realistic ever be fully closed. this work, we experimentally explore thermalization dynamics localized in controlled dissipation. Specifically, find that photon...
The recent discovery of AV_{3}Sb_{5} (A=K,Rb,Cs) has uncovered an intriguing arena for exotic Fermi surface instabilities in a kagome metal. Among them, superconductivity is found the vicinity multiple van Hove singularities, exhibiting indications unconventional pairing. We show that sublattice interference mechanism central to understanding formation Starting from appropriately chosen minimal tight-binding model with singularities close level AV_{3}Sb_{5}, we provide random phase...
Abstract Theoretically, it has been known that breaking spin degeneracy and effectively realizing spinless fermions is a promising path to topological superconductors. Yet, superconductors are rare date. Here we propose realize by splitting the in momentum space. Specifically, identify monolayer hole-doped transition metal dichalcogenide (TMD)s as candidates for out of such momentum-space-split fermions. Although electron-doped TMDs have recently found superconducting, observed...
When electric conductors differ from their mirror image, unusual chiral transport coefficients appear that are forbidden in achiral metals, such as a non-linear response known electronic magneto-chiral anisotropy (eMChA). While signatures by symmetry allowed many without center of inversion, it reaches appreciable levels only rare cases when an exceptionally strong coupling to the itinerant electrons is present. So far, observations have been limited materials which atomic positions strongly...
We report the magnetic and superconducting properties of locally noncentrosymmetric SrPtAs obtained by muon-spin-rotation/relaxation (muSR) measurements. Zero-field muSR reveals occurrence small spontaneous static fields with onset superconductivity. This finding suggests that state breaks time-reversal symmetry. The superfluid density as determined transverse field is nearly flat approaching T = 0 K proving absence extended nodes in gap function. By symmetry, several states supporting...
Recent muon spin-rotation ($\ensuremath{\mu}$SR) measurements on SrPtAs revealed time-reversal-symmetry breaking with the onset of superconductivity [Biswas et al., Phys. Rev. B 87, 180503(R) (2013)], suggesting an unconventional superconducting state. We investigate this possibility via functional renormalization group and find a chiral $(d+id)$-wave order parameter favored by multiband fermiology hexagonal symmetry SrPtAs. This state exhibits significant gap anisotropies as well...
Coupling a many-body-localized system to dissipative bath necessarily leads delocalization. Here, we investigate the nature of ensuing relaxation dynamics and information it holds on state. We formulate relevant Lindblad equation in terms local integrals motion underlying localized Hamiltonian. This allows us map quantum evolution deep state tractable classical rate equations. consider two different types dissipation systems ultracold atoms: dephasing due inelastic scattering lattice lasers...
Chiral superconductivity in 4Hb-TaS2 was discovered using muon spin rotation.
The spin-1/2 Heisenberg model on the pyrochlore lattice is an iconic frustrated three-dimensional spin system with a rich phase diagram. Besides hosting several ordered phases, debated to possess spin-liquid ground state when only nearest-neighbor antiferromagnetic interactions are present. Here, we contest this hypothesis extensive numerical investigation using both exact diagonalization and complementary variational techniques. Specifically, employ resonating-valence-bond-like,...
Abstract Tuning of electronic density-of-states singularities is a common route to unconventional metal physics. Conceptually, van Hove are realized only in clean two-dimensional systems. Little attention has therefore been given the disordered (dirty) limit. Here, we provide magnetotransport study dirty metamagnetic system calcium-doped strontium ruthenate. Fermi liquid properties persist across transition, but with an unusually strong variation Kadowaki-Woods ratio. This revealed by...
Inversion and time reversal are essential symmetries for the structure of Cooper pairs in superconductors. The loss one or both leads to modifications this can change properties superconducting phases profound ways. Lacking inversion, superconductivity noncentrosymmetric materials has become an important topic, particular, context topological as well unusual magnetic magneto-electric properties. Recently, crystal structures with local, but not global inversion-symmetry breaking have...
We present NVDRAM, the world's first dual-layer, high-performance, high-density (32Gb) and non-volatile ferroelectric memory technology. NVDRAM uses an ultra-scaled (5.7nm) capacitor as cell a dual gated, stackable, polycrystalline silicon transistor access device. To achieve high density, two layers utilizing 4F <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> architecture with 48nm pitch are fabricated above CMOS circuitry. Full package...
The triply differential cross section for the single ionization of helium by 500-eV electrons has been measured in a coplanar asymmetric geometry and analyzed using second Born-approximation treatment. It is found that these theoretical predictions concerning angular positions, shapes, magnitudes both binary recoil peaks are good agreement with experiment.
Symmetry of the crystal lattice can be a determining factor for structure Cooper pairs in unconventional superconductors. In this study we extend discussion superconductivity noncentrosymmetric materials to case when inversion symmetry is missing locally, but present on global level. Concretely, investigate staggered noncentrosymmetricity within regular sublattice structure, some analogy antiferromagnetic systems. Three structures are analyzed detail as illustrative examples extended...
We address the nature of spin-orbit torques at magnetic surfaces topological insulators using linear-response theory. find that so-called Dirac in such systems possess a different symmetry compared to their Rashba counterpart, as well high anisotropy function magnetization direction. In particular, damping torque vanishes when lies plane topological-insulator surface. also show Onsager reciprocal torque, charge pumping, induces an enhanced anisotropic damping. Via macrospin model, we...
We discuss possible pairing symmetries in the hexagonal pnictide superconductor SrPtAs. The local lack of inversion symmetry two distinct conducting layers unit cell results a special spin-orbit coupling with staggered structure. classify by global crystal point group D_3d, and suggest some candidates for stable state using tight-binding model an in-plane, density-density type interaction. may have unconventional states like s+f-wave mixture chiral d-wave p-wave. spin orbit is larger than...
Heterostructures utilizing topological insulators exhibit a remarkable spin-torque efficiency. However, the exact origin of strong torque, in particular whether it stems from spin-momentum locking surface states or rather spin-Hall physics topological-insulator bulk, remains unclear. Here, we explore mechanism generation purely based on states. We consider topological-insulator-based bilayers involving ferromagnetic metal (TI/FM) and magnetically doped (TI/mdTI), respectively. By ascribing...
The authors adapt the method of symmetry-indicators to identify nontrivial topological phases in superconductors with inversion symmetry. In particular, they introduce notion a trivial, or---in analogy insulators---'atomic' limit for Bogoliubov-de Gennes Hamiltonians as reference state topologically-trivial superconducting phase.
In the cuprates, high-temperature superconductivity, spin-density-wave order, and charge-density-wave (CDW) order are intertwined, symmetry determination is challenging due to domain formation. We investigated CDW in prototypical cuprate La_{1.88}Sr_{0.12}CuO_{4} via x-ray diffraction employing uniaxial pressure as a domain-selective stimulus establish unidirectional nature of unambiguously. A fivefold enhancement amplitude found when homogeneous superconductivity partially suppressed by...
Topological quantum chemistry (TQC) is a successful framework for identifying (noninteracting) topological materials. Based on the symmetry eigenvalues of Bloch eigenstates at maximal momenta, which are attainable from first principles calculations, band structure can either be classified as an atomic limit, in other words adiabatically connected to independent electronic orbitals respective crystal lattice, or it topological. For interacting systems, there no single-particle and hence, TQC...