papers

Publications (82)

cond-mat.mtrl-sci2017

Interplay between localization and magnetism in (Ga,Mn)As and (In,Mn)As

Ye Yuan, Chi Xu, René Hübner +6

Ion implantation of Mn combined with pulsed laser melting is employed to obtain two representative compounds of dilute ferromagnetic semiconductors (DFSs): Ga1-xMnxAs and In1-xMnxA…

cond-mat.mtrl-sci2011

Control of rectifying and resistive switching behavior in BiFeO3 thin films

Yao Shuai, Shengqiang Zhou, Chuangui Wu +6

BiFeO3 thin films have been grown on Pt/Ti/SiO2/Si substrates with pulsed laser deposition using Au as the top electrode. The resistive switching property of the Au/BiFeO3/Pt stack…

cond-mat.mtrl-sci2018

Carrier driven antiferromagnetism and exchange-bias in SrRuO3/CaRuO3 heterostructures

Parul Pandey, Ching-Hao Chang, Angus Huang +7

Oxide heterostructures exhibit a rich variety of magnetic and transport properties which arise due to contact at an interface. This can lead to surprising effects that are very dif…

cond-mat.mtrl-sci2015

Defect-induced magnetism in SiC: Interplay between ferromagnetism and paramagnetism

Yutian Wang, Yu Liu, Elke Wendler +12

Defect-induced ferromagnetism has triggered a lot of investigations and controversies. The major issue is that the induced ferromagnetic signal is so weak that it can sufficiently…

cond-mat.mtrl-sci2008

Ferromagnetic, structurally disordered ZnO implanted with Co ions

Kay Potzger, Shengqiang Zhou, Qingyu Xu +6

We present superparamagnetic clusters of structurally highly disordered Co-Zn-O created by high fluence Co ion implantation into ZnO (0001) single crystals at low temperatures. Thi…

physics.optics2021

A photonic platform hosting telecom photon emitters in silicon

Michael Hollenbach, Nagesh S. Jagtap, Ciarán Fowley +12

Silicon, a ubiquitous material in modern computing, is an emerging platform for realizing a source of indistinguishable single-photons on demand. The integration of recently discov…

cond-mat.mtrl-sci2018

Electronic phase separation in insulating (Ga,Mn)As with low compensation: Super-paramagnetism and hopping conduction

Ye Yuan, Mao Wang, Chi Xu +6

In the present work, low compensated insulating (Ga,Mn)As with 0.7% Mn is obtained by ion implantation combined with pulsed laser melting. The sample shows variable-range hopping t…

cond-mat.mes-hall2018

Carrier dynamics in graphene: ultrafast many-particle phenomena

Ermin Malic, Torben Winzer, Florian Wendler +10

Graphene is an ideal material to study fundamental Coulomb- and phonon-induced carrier scattering processes. Its remarkable gapless and linear band structure opens up new carrier r…

cond-mat.mes-hall2022

Unveiling the Zero-Phonon Line of the Boron Vacancy Center by Cavity Enhanced Emission

Chenjiang Qian, Viviana Villafañe, Martin Schalk +11

Negatively charged boron vacancies () in hexagonal boron nitride (hBN) exhibit a broad emission spectrum due to strong electron-phonon coupling and Jahn-Teller mixing of ele…

physics.optics2020

Up to 70 THz bandwidth from implanted Ge photoconductive antenna excited by a fibre laser

Abhishek Singh, Alexej Pashkin, Stephan Winnerl +6

Phase-stable electromagnetic pulses in the THz frequency range offer several unique capabilities in time-resolved spectroscopy. However, the diversity of their application is limit…

quant-ph2025

Optical spin readout of a silicon color center in the telecom L-band

Shuyu Wen, Gregor Pieplow, Junchun Yang +6

Silicon-based quantum technologies have gained increasing attention due to their potential for large-scale photonic integration, long spin coherence times, and compatibility with C…

cond-mat.mtrl-sci2018

Epitaxial Mn5Ge3 (100) layer on Ge(100) substrates obtained by flash lamp annealing

Yufang Xie, Ye Yuan, Mao Wang +7

Mn5Ge3 thin films have been demonstrated as a promising spin-injector material for germanium-based spintronic devices. So far, Mn5Ge3 has been grown epitaxially only on Ge (111) su…

cond-mat.mtrl-sci2023

Active Sites of Te-hyperdoped Silicon by Hard X-ray Photoelectron Spectroscopy

Moritz Hoesch, Olena Fedchenko, Mao Wang +10

Multiple dopant configurations of Te impurities in close vicinity in silicon are investigated using photoelectron spectroscopy, photoelectron diffraction, and Bloch wave calculatio…

quant-ph2025

Room-temperature alignment-free magnetometry with boron vacancies in hot-pressed hexagonal boron nitride

Shuyu Wen, Raul Coto, Peiting Wen +5

Magnetic field sensing is essential for applications in communication, environmental monitoring, and biomedical diagnostics. Quantum sensors based on solid-state spin defects, such…

cond-mat.mtrl-sci2024

Structural changes in Ge1-xSnx and Si1-x-yGeySnx thin films on SOI substrates treated by pulse laser annealing

Oliver Steuer, Daniel Schwarz, Michael Oehme +10

Ge1-xSnx and Si1-x-yGeySnx alloys are promising materials for future opto- and nanoelectronics applications. These alloys enable effective band-gap engineering, broad adjustability…

cond-mat.mes-hall2013

Anisotropy of excitation and relaxation of photogenerated Dirac electrons in graphene

Martin Mittendorff, Torben Winzer, Ermin Malic +6

We investigate the polarization dependence of the carrier excitation and relaxation in epitaxial multilayer graphene. Degenerate pump-probe experiments with a temporal resolution o…

cond-mat.mtrl-sci2012

InP nanocrystals on silicon for optoelectronic applications

Slawomir Prucnal, Shengqiang Zhou, Xin Ou +8

One of the solutions enabling performance progress, which can overcome the downsizing limit in silicon technology, is the integration of different functional optoelectronic devices…

cond-mat.mtrl-sci2012

Carrier dynamics in epitaxial graphene close to the Dirac point

Stephan Winnerl, Milan Orlita, Paulina Plochocka +10

We study the carrier dynamics in epitaxially grown graphene in the range of photon energies from 10 - 250 meV. The experiments complemented by microscopic modeling reveal that the…

cond-mat.mtrl-sci2024

Strong Exciton-Phonon Coupling as a Fingerprint of Magnetic Ordering in van der Waals Layered CrSBr

Kaiman Lin, Xiaoxiao Sun, Florian Dirnberger +10

The layered, air-stable van der Waals antiferromagnetic compound CrSBr exhibits pronounced coupling between its optical, electronic, and magnetic properties. As an example, exciton…

cond-mat.mtrl-sci2021

Enhanced trion emission in monolayer MoSe2 by constructing a type-I van der Waals heterostructure

Juanmei Duan, Phanish Chava, Mahdi Ghorbani-Asl +10

Trions, quasi-particles consisting of two electrons combined with one hole or of two holes with one electron, have recently been observed in transition metal dichalcogenides (TMDCs…

cond-mat.mtrl-sci2014

Structural and magnetic properties of irradiated SiC

Yutian Wang, Xuliang Chen, Lin Li +8

We present a comprehensive structural characterization of ferromagnetic SiC single crystals induced by Ne ion irradiation. The ferromagnetism has been confirmed by electron spin re…

cond-mat.mtrl-sci2019

Strain and Band-Gap Engineering in Ge-Sn Alloys via P Doping

Slawomir Prucnal, Yonder Berencén, Mao Wang +19

Ge with a quasi-direct band gap can be realized by strain engineering, alloying with Sn, or ultrahigh n-type doping. In this work, we use all three approaches together to fabricate…

cond-mat.str-el2017

Ultrafast Carrier Dynamics in VO across the Pressure-Induced Insulator-to-Metal Transition

Johannes M. Braun, Harald Schneider, Manfred Helm +5

We utilize near-infrared pump and mid-infrared probe spectroscopy to investigate the ultrafast electronic response of pressurized VO. Distinct pump-probe signals and a pumping…

physics.optics2023

On-chip lateral Si:Te PIN photodiodes for room-temperature detection in the telecom optical wavelength bands

Mohd Saif Shaikh, Shuyu Wen, Mircea-Traian Catuneanu +8

Photonic integrated circuits require photodetectors that operate at room temperature with sensitivity at telecom wavelengths and are suitable for integration with planar complement…

cond-mat.mtrl-sci2018

Symmetry-breaking supercollisions in Landau-quantized graphene

Florian Wendler, Martin Mittendorff, Jacob C. König-Otto +8

Recent pump-probe experiments performed on graphene in a perpendicular magnetic field have revealed carrier relaxation times ranging from picoseconds to nanoseconds depending on th…

cond-mat.mtrl-sci2010

The importance of hole concentration in establishing carrier-mediated ferromagnetism in Mn doped Ge

Shengqiang Zhou, Danilo Bürger, Wolfgang Skorupa +3

In the present work, we have prepared Mn-doped Ge using different annealing approaches after Mn ion implantation, and obtained samples with hole concentrations ranging from 10^18 t…

physics.app-ph2020

Silicon-based Intermediate-band Infrared Photodetector realized by Te Hyperdoping

Mao Wang, Eric García-Hemme, Yonder Berencén +7

Si-based photodetectors satisfy the criteria of low-cost and environmental-friendly, and can enable the development of on-chip complementary metal-oxide-semiconductor (CMOS)-compat…

cond-mat.mtrl-sci2011

Reduced leakage current in BiFeO3 thin films with rectifying contacts

Yao Shuai, Shengqiang Zhou, Stephan Streit +6

BiFeO3 thin films were grown on Pt/c-sapphire substrates by pulsed laser deposition with different growth rates. With increasing growth rate the leakage current is decreased and th…

cond-mat.mtrl-sci2024

Si1-x-yGeySnx alloy formation by Sn ion implantation and flash lamp annealing

Oliver Steuer, Michail Michailow, René Hübner +12

For many years, Si1-yGey alloys have been applied in the semiconductor industry due to the ability to adjust the performance of Si-based nanoelectronic devices. Following this allo…

cond-mat.mtrl-sci2016

Intrinsic diamagnetism in the Weyl semimetal TaAs

Yu Liu, Zhilin Li, Liwei Guo +6

We investigate the magnetic properties of TaAs, a prototype Weyl semimetal. TaAs crystals show weak diamagnetism with magnetic susceptibility of about -7 * 10^{-7} emu/(g*Oe) at 5…

physics.optics2025

Simple THz phase retarder based on Mach-Zehnder interferometer for polarization control

Hiroki Ueda, Alexej Pashkin, Ece Uykur +2

On-demand polarization control of electromagnetic waves is the fundamental element of modern optics. Its interest has recently been expanded in the terahertz (THz) range for cohere…

cond-mat.mtrl-sci2019

Superconductivity in single-crystalline, aluminum- and gallium-hyperdoped germanium

Slawomir Prucnal, Viton Heera, René Hübner +11

Superconductivity in group IV semiconductors is desired for hybrid devices combining both semiconducting and superconducting properties. Following boron doped diamond and Si, super…

cond-mat.mes-hall2024

Hot electron dynamics in a semiconductor nanowire under intense THz excitation

Andrei Luferau, Maximilian Obst, Stephan Winnerl +8

We report THz-pump / mid-infrared probe near-field studies on Si-doped GaAs-InGaAs core-shell nanowires utilizing THz radiation from the free-electron laser FELBE. Upon THz excitat…

cond-mat.mtrl-sci2020

Dissolution of donor-vacancy clusters in heavily doped n-type germanium

Slawomir Prucnal, Maciej O. Liedke, Xiaoshuang Wang +17

The n-type doping of Ge is a self-limiting process due to the formation of vacancy-donor complexes (DnV with n <= 4) that deactivate the donors. This work unambiguously demonstrate…

cond-mat.mtrl-sci2012

Temperature stable 1.3 μm emission from GaAs

Slawomir Prucnal, Kun Gao, Wolfgang Anwand +3

Gallium arsenide has outstanding performance in optical communication devices for light source purposes. Different approaches have been done to realize the luminescence from GaAs m…

cond-mat.mtrl-sci2018

CMOS-compatible controlled hyperdoping of silicon nanowires

Yonder Berencén, Slawomir Prucnal, Wolfhard Möller +13

Hyperdoping consists of the intentional introduction of deep-level dopants into a semiconductor in excess of equilibrium concentrations. This causes a broadening of dopant energy l…

cond-mat.mtrl-sci2017

Towards diluted magnetism in TaAs

Yu Liu, Zhilin Li, Liwei Guo +10

Magnetism in Weyl semimetals is desired to investigate the interaction between the magnetic moments and Weyl fermions, e.g. to explore anomalous quantum Hall phenomena. Here we dem…

cond-mat.mtrl-sci2012

Ferromagnetic InMnAs on InAs Prepared by Ion Implantation and Pulsed Laser Annealing

Shengqiang Zhou, Yutian Wang, Zenan Jiang +2

Ferromagnetic InMnAs has been prepared by Mn ion implantation and pulsed laser annealing. The InMnAs layer reveals a saturated magnetization of 2.6 mu_B/Mn at 5 K and a perpendicul…

cond-mat.mtrl-sci2019

Hole compensation effect in III-Mn-V dilute ferromagnetic semiconductors

Chi Xu, Mao Wang, Ye Yuan +3

A systematic study of hole compensation effect on magnetic properties, which is controlled by defect compensation through ion irradiation, in (Ga,Mn)As, (In,Mn)As and (Ga,Mn)P is p…

cond-mat.mtrl-sci2026

Revisiting the symmetry and optical phonons of altermagnetic -MnTe

Ece Uykur, Marcos V. Gonçalves-Faria, Sahana Rößler +5

Using infrared (IR) and Raman spectroscopies combined with high-resolution x-ray diffraction, we address several controversial aspects of altermagnetic -MnTe. We show that mech…

physics.optics2025

Photon emission gain in Er doped Si light emitting diodes by impact excitation

Huayou Liu, Jiayuan Zhao, Jing Zhang +6

This work demonstrates photon emission gain, i.e., emission of multiple photons per injected electron, through impact excitation in Er-doped silicon light-emitting diodes (LEDs). C…

cond-mat.mtrl-sci2022

Mid- and far-infrared localized surface plasmon resonances in chalcogen-hyperdoped silicon

Mao Wang, Ye Yu, Slawomir Prucnal +13

Plasmonic sensing in the infrared region employs the direct interaction of the vibrational fingerprints of molecules with the plasmonic resonances, creating surface-enhanced sensin…

cond-mat.mtrl-sci2015

Defect-induced magnetism in graphite through neutron irradiation

Yutian Wang, Pascal Pochet, Catherine A. Jenkins +5

We have investigated the variation in the magnetization of highly ordered pyrolytic graphite (HOPG) after neutron irradiation, which introduces defects in the bulk sample and conse…

cond-mat.mes-hall2022

Nonlinear magnon control of atomic spin defects in scalable quantum devices

Mauricio Bejarano, Francisco J. T. Goncalves, Toni Hache +10

Ongoing efforts in quantum engineering have recently focused on integrating magnonics into hybrid quantum architectures for novel functionalities. While hybrid magnon-quantum spin…

cond-mat.mtrl-sci2021

B20-MnSi films grown on Si(100) substrates with magnetic skyrmion signature

Zichao Li, Ye Yuan, René Hübner +8

Magnetic skyrmions have been suggested as information carriers for future spintronic devices. As the first material with experimentally confirmed skyrmions, B20-type MnSi was the r…

cond-mat.mtrl-sci2019

p-type codoping effect in (Ga,Mn)As: Mn lattice location versus magnetic properties

Chi Xu, Chenhui Zhang, Mao Wang +7

In the present work, we perform a systematic investigation on p-type codoping in (Ga,Mn)As. Through gradually increasing Zn doping concentration, the hole concentration increases,…

physics.optics2013

Ultrafast graphene-based broadband THz detector

Martin Mittendorff, Stephan Winnerl, Josef Kamann +4

We present an ultrafast graphene-based detector, working in the THz range at room temperature. A logarithmic-periodic antenna is coupled to a graphene flake that is produced by exf…

cond-mat.str-el2018

Non-thermal nature of photo-induced insulator-to-metal transition in NbO

Rakesh Rana, J. Michael Klopf, Jörg Grenzer +3

We study the photo-induced metallization process in niobium dioxide NbO. This compound undergoes the thermal insulator-to-metal transition at the remarkably high temperature of…

cond-mat.mtrl-sci2010

Hysteresis in the magneto-transport of Manganese-doped Germanium: evidence for carrier-mediated ferromagnetism

Shengqiang Zhou, Danilo Buerger, Arndt Muecklich +6

We report the fabrication of Ge:Mn ferromagnetic semiconductors by Mn-ion implantation into Ge followed by pulsed laser annealing. Benefiting from the short time annealing, the hol…

cond-mat.str-el2025

High-pressure modulation of breathing kagome lattice: Cascade of Lifshitz transitions and evolution of the electronic structure

Marcos V. Gonçalves-Faria, Maxim Wenzel, Yuk Tai Chan +12

The interplay between electronic correlations, density wave orders, and magnetism gives rise to several fascinating phenomena. In recent years, kagome metals have emerged as an exc…

cond-mat.mtrl-sci2023

Intrinsic magnetic properties of the layered antiferromagnet CrSBr

Fangchao Long, Kseniia Mosina, René Hübner +6

Van der Waals magnetic materials are an ideal platform to study low-dimensional magnetism. Opposed to other members of this family, the magnetic semiconductor CrSBr is highly resis…

physics.optics2022

Ultra-Broadband Visible and Infrared Light Generation Driven by Far Infrared Light in the Broad Region from 8μm to 240μm

Nils W. Rosemann, Robin C. Döring, Eike Dornsiepen +12

The most commonly used nonlinear optical process is the conversion of infrared light at 1064nm to green light at 532nm, as performed in common laser pointers. However, more relevan…

cond-mat.mtrl-sci2018

Nematicity of correlated systems driven by anisotropic chemical phase separation

Ye Yuan, René Hübner, Magdalena Birowska +12

The origin of nematicity, i.e., in-plane rotational symmetry breaking, and in particular the relative role played by spontaneous unidirectional ordering of spin, orbital, or charge…

physics.optics2024

Highly efficient broadband THz upconversion with Dirac materials

Tatiana A. Uaman Svetikova, Igor Ilyakov, Alexey Ponomaryov +16

The use of the THz frequency domain in future network generations offers an unparalleled level of capacity, which can enhance innovative applications in wireless communication, ana…

cond-mat.mtrl-sci2023

Ferromagnetic interlayer coupling in CrSBr crystals irradiated by ions

Fangchao Long, Mahdi Ghorbani-Asl, Kseniia Mosina +11

Layered magnetic materials are becoming a major platform for future spin-based applications. Particularly the air-stable van der Waals compound CrSBr is attracting considerable int…

cond-mat.mes-hall2016

Unconventional double-bended saturation of optical transmission in graphene due to many-particle interactions

Torben Winzer, Martin Mittendorff, Stephan Winnerl +3

We present a joint theory-experiment study on the transmission/absorption saturation after ultrafast pulse excitation in graphene. We reveal an unconventional double-bended saturat…

physics.optics2025

A high-performance all-silicon photodetector enabling telecom-wavelength detection at room temperature

Mohd Saif Shaikh, Mircea-Traian Catuneanu, Ahmad Echresh +9

Photonic integrated circuits (PICs) are crucial for advancing optical communications, promising substantial gains in data transmission speed, bandwidth, and energy efficiency compa…

cond-mat.mes-hall2022

Pump-induced terahertz anisotropy in bilayer graphene

Angelika Seidl, Roozbeh Anvari, Marc M. Dignam +5

We investigate the intraband nonlinear dynamics in doped bilayer graphene in the presence of strong, linearly-polarized, in-plane terahertz fields. We perform degenerate pump-probe…

cond-mat.supr-con2023

Possible Eliashberg-type superconductivity enhancement effects in a two-band superconductor MgB2 driven by narrow-band THz pulses

Sergei Sobolev, Amon Lanz, Tao Dong +12

We study THz-driven condensate dynamics in epitaxial thin films of MgB, a prototype two-band superconductor (SC) with weak interband coupling. The temperature and excitation…

cond-mat.mtrl-sci2017

Interaction between magnetic moments and itinerant carriers in d0 ferromagnetic SiC

Yu Liu, Ye Yuan, Fang Liu +12

Elucidating the interaction between magnetic moments and itinerant carriers is an important step to spintronic applications. Here, we investigate magnetic and transport properties…

cond-mat.mtrl-sci2014

Disentangling defect-induced ferromagnetism in SiC

Yutian Wang, Lin Li, Slawomir Prucnal +9

We present a detailed investigation of the magnetic properties in SiC single crystals bombarded with neon ions. Through careful measuring of the magnetization of virgin and irradia…

cond-mat.mtrl-sci2009

Memory effect of MnGe nanomagnets embedded inside a Mn-diluted Ge matrix

Shengqiang Zhou, Artem Shalimov, Kay Potzger +5

Crystalline Mn5Ge3 nanomagnets are formed inside a Mn-diluted Ge matrix using Mn ion implantation. A temperature-dependent memory effect and slow magnetic relaxation are observed b…

cond-mat.mes-hall2020

Nonlinear Charge Transport in InGaAs Nanowires at Terahertz Frequencies

Rakesh Rana, Leila Balaghi, Ivan Fotev +4

We probe the electron transport properties in the shell of GaAs/In0.2Ga0.8As core/shell nanowires at high electric fields using optical pump / THz probe spectroscopy with broadband…

cond-mat.mtrl-sci2011

Nonvolatile bipolar resistive switching in Au/BiFeO3/Pt

Yao Shuai, Shengqiang Zhou, Danilo Bürger +2

Nonvolatile bipolar resistive switching has been observed in an Au/BiFeO3/Pt structure, where a Schottky contact and a quasi-Ohmic contact were formed at the Au/BiFeO3 and BiFeO3/P…

cond-mat.mtrl-sci2020

Topological Hall effect in single thick SrRuO3 layers induced by defect engineering

Changan Wang, Ching-Hao Chang, Andreas Herklotz +11

The topological Hall effect (THE) has been discovered in ultrathin SrRuO3 (SRO) films, where the interface between the SRO layer and another oxide layer breaks the inversion symmet…

cond-mat.mtrl-sci2021

Chlorine doping of MoSe2 flakes by ion implantation

Slawomir Prucnal, Arsalan Hashemi, Mahdi Ghorbani-Asl +10

The efficient integration of transition metal dichalcogenides (TMDs) into the current electronic device technology requires mastering the techniques of effective tuning of their op…

cond-mat.mtrl-sci2018

Defect-induced exchange bias in a single SrRuO3 layer

Changan Wang, Chao Chen, Ching-Hao Chang +9

Exchange bias stems from the interaction between different magnetic phases and therefore it generally occurs in magnetic multilayers. Here we present a large exchange bias in a sin…

cond-mat.mtrl-sci2011

Decisive role of oxygen vacancy in ferroelectric vs. ferromagnetic Mn-doped BaTiO3 thin films

Yao Shuai, Shengqiang Zhou, Danilo Bürger +5

Single-phase perovskite 5 at.% Mn-doped and undoped polycrystalline BaTiO3 thin films have been grown under different oxygen partial pressures by pulsed laser deposition on platinu…

cond-mat.mes-hall2024

Probing the band splitting near the point in the van der Waals magnetic semiconductor CrSBr

Kaiman Lin, Yi Li, Mahdi Ghorbani-Asl +8

This study investigates the electronic band structure of Chromium Sulfur Bromide (CrSBr) through comprehensive photoluminescence (PL) characterization. We clearly identify low-temp…

cond-mat.mtrl-sci2022

Terahertz control of photoluminescence emission in few-layer InSe

Tommaso Venanzi, Malte Selig, Alexej Pashkin +11

A promising route for the development of opto-elelctronic technology is to use terahertz radiation to modulate the optical properties of semiconductors. Here we demonstrate the dyn…

cond-mat.mtrl-sci2022

On Curie temperature of B20-MnSi films

Zichao Li, Ye Yuan, Viktor Begeza +5

B20-type MnSi is the prototype magnetic skyrmion material. Thin films of MnSi show a higher Curie temperature than their bulk counterpart. However, it is not yet clear what mechani…

cond-mat.mtrl-sci2012

Substrate effect on the resistive switching in BiFeO3 thin films

Yao Shuai, Xin Ou, Chuangui Wu +8

BiFeO3 thin films have been deposited on Pt/sapphire and Pt/Ti/SiO2/Si substrates with pulsed laser deposition using the same growth conditions, respectively. Au was sputtered as t…

cond-mat.mtrl-sci2009

Anomalous Hall resistance in Ge:Mn systems with low Mn concentrations

Shengqiang Zhou, Danilo Buerger, Manfred Helm +1

Taking Mn doped Germanium as an example, we evoke the consideration of a two-band-like conduction in diluted ferromagnetic semiconductor (FMS). The main argument for claiming Ge:Mn…

cond-mat.mtrl-sci2018

Tunable disorder and localization in the rare-earth nickelates

Changan Wang, Ching-Hao Chang, Angus Huang +13

The rare-earth nickelates are a rich playground for transport properties, known to host non-Fermi liquid character, resistance saturation and metal-insulator transitions. We report…

cond-mat.supr-con2023

Ultrafast Relaxation Dynamics of Spin-Density Wave Order in BaFeAs under High Pressures

Ivan Fotev, Stephan Winnerl, Saicharan Aswartham +5

BaFeAs is the parent compound for a family of iron-based high-temperature superconductors as well as a prototypical example of the spin-density wave (SDW) system. In this s…

cond-mat.mes-hall2013

Reverse epitaxy of Ge: ordered and facetted surface patterns

Xin Ou, Adrian Keller, Manfred Helm +2

Normal incidence ion irradiation at elevated temperatures, when amorphization is prevented, induces novel nanoscale patterns of crystalline structures on elemental semiconductors b…

cond-mat.mtrl-sci2008

Room temperature ferromagnetism in carbon-implanted ZnO

Shengqiang Zhou, Qingyu Xu, Kay Potzger +10

Unexpected ferromagnetism has been observed in carbon doped ZnO films grown by pulsed laser deposition [Phys. Rev. Lett. 99, 127201 (2007)]. In this letter, we introduce carbon int…

quant-ph2022

Extending the coherence time of spin defects in hBN enables advanced qubit control and quantum sensing

Roberto Rizzato, Martin Schalk, Stephan Mohr +10

Spin defects in hexagonal Boron Nitride (hBN) attract increasing interest for quantum technology since they represent optically-addressable qubits in a van der Waals material. In p…

cond-mat.mtrl-sci2009

Spin-dependent transport in nanocomposite C:Co films

Shengqiang Zhou, Markus Berndt, Danilo Buerger +10

The magneto-transport properties of nanocomposite C:Co (15 and 40 at.% Co) thin films are investigated. The films were grown by ion beam co-sputtering on thermally oxidized silicon…

cond-mat.mes-hall2023

Emitter-Optomechanical Interaction in Ultra-High-Q hBN Nanocavities

Chenjiang Qian, Viviana Villafañe, Martin Schalk +6

Integrating quantum emitters into nanocavities which simultaneously couple to the photonic and mechanical modes is critical for interfacing electron spins, photons and phonons in t…

cond-mat.mes-hall2020

Photoluminescence dynamics in few-layer InSe

Tommaso Venanzi, Himani Arora, Stephan Winnerl +10

We study the optical properties of thin flakes of InSe encapsulated in hBN. More specifically, we investigate the photoluminescence (PL) emission and its dependence on sample thick…

cond-mat.mtrl-sci2019

Tuning the metal-insulator transition in epitaxial SrVO3 films by uniaxial strain

Changan Wang, Hongbin Zhang, Kumar Deepak +12

Understanding of the metal-insulator transition (MIT) in correlated transition-metal oxides is a fascinating topic in condensed matter physics and a precise control of such transit…