Publications (20)
Optical control of conductivity type and valley polarization via persistent photoconductivity in (Pb,Sn)Se quantum wells
Alexander Kazakov, Gauthier Krizman, Valentine V. Volobuev +8
The ability to tune the Fermi level of semiconductors is at the heart of modern electronics. Here, we demonstrate that persistent photoconductivity (PPC) enables tuning of carrier…
Step-edge assisted large scale FeSe monolayer growth on epitaxial Bi2Se3 thin films
Jan FikáÄek, Vitalii Stetsovych, Martin VondráÄek +10
The interest in Fe-chalcogenide unconventional superconductors is intense after the critical temperature of FeSe was reported enhanced by more than one order of magnitude in the mo…
Field-induced ultrafast modulation of Rashba coupling at room temperature in ferroelectric -GeTe(111)
Geoffroy Kremer, Julian Maklar, Laurent Nicolaï +11
Rashba materials have appeared as an ideal playground for spin-to-charge conversion in prototype spintronics devices. Among them, -GeTe(111) is a non-centrosymmetric ferroelect…
Entropy controlled fully reversible nanostructure formation of Ge on miscut vicinal Si (001) surfaces
Christian Grossauer, Vaclv Holy, Gunther Springholz
Entropy effects substantially modify the growth of self-assembled Ge nanostructures on vicinal Si (001) surfaces. As shown by variable temperature scanning tunneling microscopy, th…
Probing Berry curvature in magnetic topological insulators through resonant infrared magnetic circular dichroism
Seul-Ki Bac, Florian le Mardelé, Jiashu Wang +16
Probing the quantum geometry and topology in condensed matter systems has relied heavily on static electronic transport experiments in magnetic fields. Yet, contact-free optical me…
Persistence of structural distortion and bulk band Rashba splitting in SnTe above its ferroelectric critical temperature
Frédéric Chassot, Aki Pulkkinen, Geoffroy Kremer +8
The ferroelectric semiconductor -SnTe has been regarded as a topological crystalline insulator and the dispersion of its surface states has been intensively measured with angle…
Ultrafast dynamics of optically excited charge carriers in the room-temperature antiferromagnetic semiconductor -MnTe
Changqing Zhu, Patrick Pilch, Anneke Reinold +6
We report on time-resolved optical and terahertz ultrafast spectroscopy of charge-carrier dynamics in the room-temperature antiferromagnetic semiconductor -MnTe. By optically p…
Anomalous Spectroscopical Effects in an Antiferromagnetic Semiconductor
Michal Hubert, Tomáš MaleÄek, Kyo-Hoon Ahn +6
Following the recent observation of anomalous Hall effect in antiferromagnetic hexagonal MnTe thin films, related phenomena at finite frequencies have come into focus. Magnetic cir…
Conduction Band Structure and Ultrafast Dynamics of Ferroelectric -GeTe(111)
Geoffroy Kremer, Laurent Nicolaï, Frédéric Chassot +9
-GeTe(111) is a non-centrosymmetric ferroelectric (FE) material for which a significative lattice distortion combined with a strong spin-orbit interaction gives rise to giant R…
Probing the magnetic band gap of the ferromagnetic topological insulator MnSbTe
Philipp Küppers, Jannik Zenner, Stefan Wimmer +4
Mn-rich MnSbTe is a ferromagnetic topological insulator with yet the highest Curie temperature T_C = 45-50 K. It exhibits a magnetic gap at the Dirac point of the topologic…
Magnetooptical determination of a topological index
Badih A. Assaf, Thanyanan Phuphachong, Valentine V. Volobuev +4
When a Dirac fermion system acquires an energy-gap, it is said to have either trivial (positive energy-gap) or non-trivial (negative energy-gap) topology, depending on the parity o…
Triple point fermions in ferroelectric GeTe
Juraj Krempaský, Laurent Nicolaï, Martin Gmitra +10
Ferroelectric GeTe is unveiled to exhibit an intriguing multiple non-trivial topology of the electronic band structure due to the existence of triple-point and type-II Weyl fermion…
Signatures of dephasing by mirror-symmetry breaking in weak-antilocalization magnetoresistance across the topological transition in PbSnSe
Alexander Kazakov, Wojciech Brzezicki, Timo Hyart +12
Many conductors, including recently studied Dirac materials, show saturation of coherence length on decreasing temperature. This surprising phenomenon is assigned to external noise…
A Novel Ferroelectric Rashba Semiconductor
Gauthier Krizman, Tetiana Zakusylo, Lakshmi Sajeev +8
Fast, reversible, and low-power manipulation of the spin texture is crucial for next generation spintronic devices like non-volatile bipolar memories, switchable spin current injec…
Detection of Image Potential States above the vacuum level in GeTe
Frédéric Chassot, Aki Pulkkinen, Ján Minár +3
The ferroelectric semiconductor α-GeTe(111) has attracted significant attention in the last decade due to its unique properties, with extensive studies focusing on its occupied el…
Magnetically tunable symmetry-enforced nodal lines producing huge anomalous Hall conductivity in altermagnetic -MnTe
Mathews Benny, Xujia Gong, Amar Fakhredine +15
Altermagnetic -MnTe exhibits huge anomalous Hall conductivity (AHC) up to room-temperature together with weak ferromagnetism arising from spin and orbital polarizations. We cla…
Anisotropic magnetoresistance in altermagnetic MnTe
Ruben Dario Gonzalez Betancourt, Jan ZubáÄ, Kevin Geishendorf +12
Recently, MnTe was established as an altermagnetic material that hosts spin-polarized electronic bands as well as anomalous transport effects like the anomalous Hall effect. In add…
Collective topological spin dynamics in a correlated spin glass
Juraj Krempaský, Gunther Springholz, Sunil Wilfred D'Souza +12
The interplay between spin-orbit interaction (SOI) and magnetic order is currently one of the most active research fields in condensed matter physics and leading the search for mat…
Topological phase diagram and quantum magnetotransport effects in (Pb,Sn)Se quantum wells with magnetic barriers (Pb,Eu)Se
Alexander Kazakov, Valentine V. Volobuev, Chang-Woo Cho +6
In this study, we report here on a successful growth by molecular beam epitaxy of high crystalline quality PbSnSe:Bi/PbEuSe QWs with and $y =…
Interaction between interface and massive states in multivalley topological heterostructures
Gauthier Krizman, Badih A. Assaf, Milan Orlita +5
Topological interface states in multivalley systems are studied to unravel their valley sensitivity. For this purpose, multivalley IV-VI topological crystalline insulator (TCI) het…