Publications (27)
Anisotropic two-dimensional screening at the surface of black phosphorus
Brian Kiraly, Elze J. Knol, Klara Volckaert +8
Screening in reduced dimensions has strong consequences on the electronic properties in van der Waals semiconductors, impacting the quasiparticle band gap and exciton binding energ…
Hybrid Photoelectron Momentum Microscope at the Soft X-ray Beamline I09 of the Diamond Light Source
Matthias Schmitt, Deepnarayan Biswas, Olena Tkach +7
Soft X-ray momentum microscopy of crystalline solids is a highly efficient approach to map the photoelectron distribution in four-dimensional (E,k) parameter space over the entire…
Momentum-resolved view of highly tunable many-body effects in a graphene/hBN field-effect device
Ryan Muzzio, Alfred J. H. Jones, Davide Curcio +12
Integrating the carrier tunability of a functional two-dimensional material electronic device with a direct probe of energy- and momentum-resolved electronic excitations is essenti…
Visualizing band structure hybridization and superlattice effects in twisted MoS/WS heterobilayers
Alfred J. H. Jones, Ryan Muzzio, Sahar Pakdel +16
A mismatch of atomic registries between single-layer transition metal dichalcogenides (TMDs) in a two dimensional van der Waals heterostructure produces a moiré superlattice with…
Identification of the surface features in the electronic structure of Cr
Khadiza Ali, Shyama R. Varier, Deepnarayan Biswas +2
We studied the electronic structure of high quality Cr(110) films grown on W(110) surface employing photoemission spectroscopy. Experiments on the differently aged samples revealed…
Selective control of localised vs. delocalised carriers in anatase TiO2 through reaction with O2
Chiara Bigi, Zhenkun Tang, Gian Marco Pierantozzi +16
Two-dimensional (2D) metallic states induced by oxygen vacancies at oxide surfaces and interfaces provide new opportunities for the development of advanced applications, but the ab…
Clustering-Enhanced Time- and Angle-Resolved Photoemission Study of LaTe: Absence of a Photoinduced Secondary CDW in the Electronic Structure
Gesa-R. Siemann, Davide Curcio, Anders S. Mortensen +9
Optical control offers a compelling route for tailoring material properties on an ultrafast time scale. Ordered states such as charge density waves (CDWs) can be transiently melted…
Epitaxial growth of a two-dimensional topological insulator candidate: monolayer Si2Te2
Xiaochun Huang, Rui Xiong, Klara Volckaert +9
Hexagonal Si2Te2 monolayers (ML-Si2Te2) were predicted to show strain-dependent band-crossover between semiconducting and room-temperature quantum spin Hall phases. However, invest…
Hot carrier-assisted switching of the electron-phonon interaction in 1-VSe
Paulina Majchrzak, Sahar Pakdel, Deepnarayan Biswas +20
We apply an intense infrared laser pulse in order to perturb the electronic and vibrational states in the three-dimensional charge density wave material 1-VSe. Ultrafast sna…
Electronic structure studies on single crystalline Nd2PdSi3, an exotic Nd-based intermetallic: Evidence for Nd 4f hybridization
Kalobaran Maiti, Tathamay Basu, Sangeeta Thakur +6
In the series R2PdSi3, Nd2PdSi3 is an anomalous compound in the sense that it exhibits ferromagnetic order unlike other members in this family. The magnetic ordering temperature is…
Transient Hot Electron Dynamics in Single-Layer TaS
Federico Andreatta, Habib Rostami, Antonija GrubiÅ¡iÄ Äabo +12
Using time- and angle-resolved photoemission spectroscopy, we study the response of metallic single layer TaS in the 1H structural modification to the generation of excited car…
Dielectric and gate metal engineering for threshold voltage modulation in enhancement mode monolayer MoS2 field effect transistors
Lixin Liu, Han Yan, Leyi Loh +8
Excellent gate electrostatics in field effect transistors (FETs) based on two-dimensional transition metal dichalcogenide (2D TMD) channels can dramatically decrease static power d…
Mixed ground state in Fe-Ni Invar alloys
S. S. Acharya, V. R. R. Medicherla, Komal Bapna +4
We investigate the ground state properties of Invar alloys via detailed study of the electronic structure of FeNi alloys ( = 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.9) emplo…
External screening and lifetime of exciton population in single-layer ReSe probed by time- and angle-resolved photoemission spectroscopy
Klara Volckaert, Byoung Ki Choi, Hyuk Jin Kim +7
The semiconductor ReSe is characterized by a strongly anisotropic optical absorption and is therefore promising as an optically active component in two-dimensional heterostruct…
Ultrafast triggering of insulator-metal transition in two-dimensional VSe
Deepnarayan Biswas, Alfred J. H. Jones, Paulina Majchrzak +24
Assembling transition metal dichalcogenides (TMDCs) at the two-dimensional (2D) limit is a promising approach for tailoring emerging states of matter such as superconductivity or c…
Accessing the spectral function in a current-carrying device
Davide Curcio, Alfred J. H. Jones, Ryan Muzzio +12
The presence of an electrical transport current in a material is one of the simplest and most important realisations of non-equilibrium physics. The current density breaks the crys…
Anomalies in the electronic structure of Bi(2)Se(3)
Deepnarayan Biswas, Kalobaran Maiti
We studied the electronic structure Bi(2)Se(3) employing density functional theory. The calculations show that the Dirac states primarily consists of the states at the interface of…
Momentum-resolved linear dichroism in bilayer MoS
Klara Volckaert, Habib Rostami, Deepnarayan Biswas +19
Inversion-symmetric crystals are optically isotropic and thus naively not expected to show dichroism effects in optical absorption and photoemission processes. Here, we find a stro…
Spin and Valley Control of Free Carriers in Single-Layer WS
Søren Ulstrup, Antonija GrubiÅ¡iÄ Äabo, Deepnarayan Biswas +11
The semiconducting single-layer transition metal dichalcogenides have been identified as ideal materials for accessing and manipulating spin- and valley-quantum numbers due to a se…
Programming moiré patterns in 2D materials by bending
Mäelle Kapfer, Bjarke S. Jessen, Megan E. Eisele +20
Moiré superlattices in twisted two-dimensional materials have generated tremendous excitement as a platform for achieving quantum properties on demand. However, the moiré pattern…
Local excitons in silicon induced by SiGe quantum huts
Arka Bikash Dey, Milan K Sanyal, Swapnil Patil +4
Conversion of Si to a direct bandgap semiconductor for optoelectronic application is a great challenge for many decades. It is proposed that embedment of suitable sized quantum dot…
Nanoscale view of engineered massive Dirac quasiparticles in lithographic superstructures
Alfred J. H. Jones, Lene Gammelgaard, Mikkel O. Sauer +13
Massive Dirac fermions are low-energy electronic excitations characterized by a hyperbolic band dispersion. They play a central role in several emerging physical phenomena such as…
Observation of Electrically Tunable van Hove Singularities in Twisted Bilayer Graphene from nanoARPES
Alfred J. H. Jones, Ryan Muzzio, Paulina Majchrzak +16
The possibility of triggering correlated phenomena by placing a singularity of the density of states near the Fermi energy remains an intriguing avenue towards engineering the prop…
Van der Waals engineering of ultrafast carrier dynamics in magnetic heterostructures
Paulina Majchrzak, Yuntian Liu, Klara Volckaert +10
Heterostructures composed of the intrinsic magnetic topological insulator MnBiTe and its non-magnetic counterpart BiTe host distinct surface electronic band structu…
Pnictogens Allotropy and Phase Transformation during van der Waals Growth
Matthieu Fortin-Deschênes, Hannes Zschiesche, Tevfik O. MenteŠ+13
Pnictogens have multiple allotropic forms resulting from their ns2 np3 valence electronic configuration, making them the only elemental materials to crystallize in layered van der…
Aging of the surface of Bi(2)Se(3)
Deepnarayan Biswas, Sangeeta Thakur, Khadiza Ali +2
We study the electronic structure of Bi(2)Se(3) employing high resolution photoemission spectroscopy and discover the dependence of the behavior of Dirac particles on surface termi…
Interplay of electron correlation and covalency in FeTe(0.6)Se(0.4)
Ganesh Adhikary, Deepnarayan Biswas, Nishaina Sahadev +5
We investigate the electronic structure of FeTe(0.6)Se(0.4) employing high resolution photoemission spectroscopy and ab initio band structure calculations. Fe 2p core level and the…