Publications de Philip Johannes Walter Moll

Nonlinear optical diode effect in a magnetic Weyl semimetal

Philip Johannes Walter Moll, Chunyu Guo, Hao Yang

Diode effects are of great interest for both fundamental physics and modern technologies. Electrical diode effects (nonreciprocal transport) have been observed in Weyl systems. Optical diode effects arising from the Weyl fermions have been theoretically co ...

Nature Portfolio2024

Controlling crystal cleavage in focused ion beam shaped specimens for surface spectroscopy

Philip Johannes Walter Moll, Matthias Carsten Putzke, Andrew Scott Hunter

Our understanding of quantum materials is commonly based on precise determinations of their electronic spectrum by spectroscopic means, most notably angle-resolved photoemission spectroscopy (ARPES) and scanning tunneling microscopy. Both require atomicall ...

Aip Publishing2024

Hierarchy of quasisymmetries and degeneracies in the CoSi family of chiral crystal materials

Yi-Chiang Sun, Philip Johannes Walter Moll, Chunyu Guo

In materials, certain approximated symmetry operations can exist in a lower-order approximation of the effective model but are good enough to influence the physical responses of the system, and these approximated symmetries were recently dubbed "quasisymme ...

AMER PHYSICAL SOC2023

Layered metals as polarized transparent conductors

Philip Johannes Walter Moll, Matthias Carsten Putzke, Chunyu Guo, Maja Deborah Bachmann

The quest to improve transparent conductors balances two key goals: increasing electrical conductivity and increasing optical transparency. To improve both simultaneously is hindered by the physical limitation that good metals with high electrical conducti ...

Nature Portfolio2023

Crossing the ballistic-ohmic transition via high energy electron irradiation

Philip Johannes Walter Moll, Matthias Carsten Putzke, Maja Deborah Bachmann

The delafossite metal PtCoO2 is among the highest-purity materials known, with low-temperature mean free path up to 5 mu m in the best as-grown single crystals. It exhibits a strongly faceted, nearly hexagonal Fermi surface. This property has profound cons ...

AMER PHYSICAL SOC2023

Reply to: Low-frequency quantum oscillations in LaRhIn5: Dirac point or nodal line?

Oleg Yazyev, Quansheng Wu, Amelia Emily-Kay Estry, Shengnan Zhang, Philip Johannes Walter Moll, Matthias Carsten Putzke, Chunyu Guo

Nature Portfolio2023

Quasi-symmetry-protected topology in a semi-metal

Yi-Chiang Sun, Xiangwei Huang, Philip Johannes Walter Moll, Jonas De Jesus Diaz Gomez, Matthias Carsten Putzke, Chunyu Guo

The concept of quasi-symmetry-a perturbatively small deviation from exact symmetry-is introduced and leads to topological materials with strong resilience to perturbations. ...

NATURE PORTFOLIO2022

Controlling superconductivity of CeIrIn5 microstructures by substrate selection

Philip Johannes Walter Moll, Matthias Carsten Putzke, Chunyu Guo, Maja Deborah Bachmann, Maarten Ruud van Delft, Joshua Alan Wolfe Straquadine

Superconductor/metal interfaces are usually fabricated in heterostructures that join these dissimilar materials. A conceptually different approach has recently exploited the strain sensitivity of heavy-fermion superconductors, selectively transforming regi ...

AIP Publishing2022

Three-dimensional Fermi surfaces from charge order in layered CsV3Sb5

Yi-Chiang Sun, Xiangwei Huang, Philip Johannes Walter Moll, Matthias Carsten Putzke, Chunyu Guo

The cascade of electronic phases in CsV3Sb5 raises the prospect to disentangle their mutual interactions in a clean, strongly interacting kagome lattice. When the kagome planes are stacked into a crystal, its electronic dimensionality encodes how much of t ...

AMER PHYSICAL SOC2022

Ionic Liquid Gating of SrTiO3 Lamellas Fabricated with a Focused Ion Beam

Evgeny Mikheev, Amelia Emily-Kay Estry, Philip Johannes Walter Moll

In this work, we combine two previously incompatible techniques for defining electronic devices: shaping three-dimensional crystals by focused ion beam (FIB), and two-dimensional electrostatic accumulation of charge carriers. The principal challenge for th ...

AMER CHEMICAL SOC2022

Bending strain in 3D topological semi-metals

Amelia Emily-Kay Estry, Xiangwei Huang, Philip Johannes Walter Moll, Jonas De Jesus Diaz Gomez, Matthias Carsten Putzke

We present an experimental set-up for the controlled application of strain gradients by mechanical piezoactuation on 3D crystalline microcantilevers that were fabricated by focused ion beam machining. A simple sample design tailored for transport character ...

IOP Publishing Ltd2022

Antiskyrmions and their electrical footprint in crystalline mesoscale structures of Mn1.4PtSn

Philip Johannes Walter Moll

Skyrmionic materials hold the potential for future information technologies, such as racetrack memories. Key to that advancement are systems that exhibit high tunability and scalability, with stored information being easy to read and write by means of all- ...

2022

Electrical control of glass-like dynamics in vanadium dioxide for data storage and processing

Andras Kis, Andreas Schueler, Anna Krammer, Elison de Nazareth Matioli, Reza Soleiman Zadeh Ardebili, Mohammad Samizadeh Nikooytabalvandani, Philip Johannes Walter Moll, Guilherme Migliato Marega

Metal–oxide–semiconductor junctions are the building blocks of modern electronics and can provide a variety of functionalities, from memory to computing. The technology, however, faces constraints in terms of further miniaturization and compatibility with ...

2022

Mesoscopic finite-size effects of unconventional electron transport in PdCoO2

Philip Johannes Walter Moll

A wide range of unconventional transport phenomena has recently been observed in single-crystal delafossite metals. Here, we present a theoretical framework to elucidate electron transport using a combination of first-principles calculations and numerical ...

2022

Evidence of a coupled electron-phonon liquid in NbGe2

Mathieu François Padlewski, Philip Johannes Walter Moll, Matthias Carsten Putzke, Hao Yang

Whereas electron-phonon scattering relaxes the electron's momentum in metals, a perpetual exchange of momentum between phonons and electrons may conserve total momentum and lead to a coupled electron-phonon liquid. Such a phase of matter could be a platfor ...

Nature Portfolio2021

Non-linear Shubnikov-de Haas oscillations in the self-heating regime

Xiangwei Huang, Philip Johannes Walter Moll, Jonas De Jesus Diaz Gomez, Matthias Carsten Putzke, Chunyu Guo

We demonstrate a non-linear measurement scheme of the Shubnikov-de Haas effect based on Joule self-heating that builds on ideas of the 3 ?-method used in thin films. While the temperature dependence of the resistance, R(T), of clean metals at low temperatu ...

AIP Publishing2021

Sondheimer oscillations as a probe of non-ohmic flow in WP2 crystals

Jacopo Oswald, Yi-Chiang Sun, Philip Johannes Walter Moll, Jonas De Jesus Diaz Gomez, Matthias Carsten Putzke, Chunyu Guo, Maarten Ruud van Delft

As conductors in electronic applications shrink, microscopic conduction processes lead to strong deviations from Ohm's law. Depending on the length scales of momentum conserving (l(MC)) and relaxing (l(MR)) electron scattering, and the device size (d), cur ...

Nature Portfolio2021

Crystal Structures of AlCr2 and MoSi2: Same Structure Type vs. Different Bonding Pattern

Philip Johannes Walter Moll

In a joint effort utilizing modified sample preparation, microscopy, X-ray diffraction and micro-fabrication, it became possible to prepare single crystals of the "hidden" phase AlCr2. High-resolution X-ray diffraction analysis is described in detail for t ...

2021

Unidirectional Kondo scattering in layered NbS2

Helmuth Berger, László Forró, Oleg Yazyev, Christoph Koch, Edoardo Martino, Quansheng Wu, Shengnan Zhang, Philip Johannes Walter Moll, Matthias Carsten Putzke, Konstantin Semeniuk

Crystalline defects can modify quantum interactions in solids, causing unintuitive, even favourable, properties such as quantum Hall effect or superconducting vortex pinning. Here we present another example of this notion-an unexpected unidirectional Kondo ...

NATURE PORTFOLIO2021

Scanning SQUID microscopy in a cryogen-free dilution refrigerator

Philip Johannes Walter Moll, Maja Deborah Bachmann

We report a scanning superconducting quantum interference device (SQUID) microscope in a cryogen-free dilution refrigerator with a base temperature at the sample stage of at least 30 mK. The microscope is rigidly mounted to the mixing chamber plate to opti ...

2021