Publications (56)
Magnetism in the 2D Limit and Interface Superconductivity in Metal-Insulator La(2-x)Sr(x)CuO(4) Superlattices
A. Suter, E. Morenzoni, T. Prokscha +6
We show, by means of low-energy muon spin rotation measurements, that few-unit-cells thick La(2)CuO(4) layers synthesized digitally by molecular beam epitaxy synthesis are antiferr…
Direct spectroscopic observation of a shallow hydrogen-like donor state in insulating SrTiO
Z. Salman, T. Prokscha, A. Amato +4
We present a direct spectroscopic observation of a shallow hydrogen-like muonium state in SrTiO which confirms the theoretical prediction that interstitial hydrogen may act as…
Direct observation of the oxygen isotope effect on the in-plane magnetic field penetration depth in optimally doped YBaCuO
R. Khasanov, D. G. Eshchenko, H. Luetkens +8
We report the first direct observation of the oxygen-isotope (O/O) effect on the in-plane penetration depth in a nearly optimally doped YBaCuO$_{7-Î…
Magnetic order of tetragonal CuO ultra-thin films
N. Ortiz Hernandez, Z. Salman, T. Prokscha +6
We present a detailed low-energy muon spin rotation and x-ray magnetic circular dichroism (XMCD) investigation of the magnetic structure in ultra-thin tetragonal (T)-CuO films. The…
Intertwined magnetic, structural, and electronic transitions in VO
Benjamin A. Frandsen, Yoav Kalcheim, Ilya Valmianski +15
We present a coordinated study of the paramagnetic-to-antiferromagnetic, rhombohedral-to-monoclinic, and metal-to-insulator transitions in thin-film specimens of the classic Mott i…
Do topology and ferromagnetism cooperate at the EuS/BiSe interface?
J. A. Krieger, Y. Ou, M. Caputo +10
We probe the local magnetic properties of interfaces between the insulating ferromagnet EuS and the topological insulator BiSe using low energy muon spin rotation (LE-S…
Depth-dependent magnetic crossover in a room-temperature skyrmion-hosting multilayer
T. J. Hicken, M. N. Wilson, Z. Salman +8
Skyrmion-hosting multilayer stacks are promising avenues for applications, although little is known about the depth dependence of the magnetism. We address this by reporting the re…
Experimental study of the magnetic field distribution and shape of domains near the surface of type-I superconductors in the intermediate state
V. Kozhevnikov, A. Suter, T. Prokscha +1
The importance of accounting for the inhomogeneity of the magnetic field distribution and roundness of domain walls near the surface of type-I superconductors in the intermediate s…
Remotely induced magnetism in a normal metal using a superconducting spin-valve
M. G. Flokstra, N. Satchell, J. Kim +13
Superconducting spintronics has emerged in the last decade as a promising new field that seeks to open a new dimension for nanoelectronics by utilizing the internal spin structure…
Nanoscale layering of antiferromagnetic and superconducting phases in Rb2Fe4Se5
A. Charnukha, A. Cvitkovic, T. Prokscha +10
We studied phase separation in a single-crystalline antiferromagnetic superconductor Rb2Fe4Se5 (RFS) using a combination of scattering-type scanning near-field optical microscopy (…
Sulfur-induced magnetism in FeSeS thin films on LaAlO revealed by muon spin rotation/relaxation
F. Nabeshima, Y. Kawai, N. Shikama +8
Muon spin rotation/relaxation measurements were performed to investigate magnetic properties of FeSeS thin films on LaAlO. A drastic decrease of the initial asymmet…
Direct evidence of superconductivity and determination of the superfluid density in buried ultrathin FeSe grown on SrTiO
P. K. Biswas, Z. Salman, Q. Song +6
Bulk FeSe is superconducting with a critical temperature 8 K and SrTiO is insulating in nature, yet high-temperature superconductivity has been reported at the in…
Magnetic Fluctuations in Niobium Pentoxide
Y. Krasnikova, A. A. Murthy, F. Crisa +10
Using a spin-polarized muon beam we were able to capture magnetic dynamics in an amorphous niobium pentoxide thin film. Muons are used to probe internal magnetic fields produced by…
Proximal magnetometry of monolayers of single molecule magnets on gold using polarized muons
Z. Salman, S. J. Blundell, S. R. Giblin +7
The magnetic properties of a monolayer of Fe4 single molecule magnets grafted onto a Au (111) thin film have been investigated using low energy muon spin rotation. The properties o…
Pressure induced transition from chiral charge order to time-reversal symmetry-breaking superconducting state in Nb-doped CsVSb
J. N. Graham, S. S. Islam, V. Sazgari +19
The experimental realisation of unconventional superconductivity and charge order in kagome systems \textit{A}VSb is of critical importance. We conducted a highly systemati…
Direct observation of hole carrier density profiles and their light induced manipulation at the surface of Ge
T. Prokscha, K. H. Chow, Z. Salman +2
We demonstrate that, by using low-energy positive muon () spin spectroscopy as a local probe technique, the profiles of free charge carriers can be directly determined in the…
The Nature of Magnetic Ordering in Magnetically Doped Topological Insulator BiFeSe
Z. Salman, E. Pomjakushina, V. Pomjakushin +7
We present a detailed investigation of the magnetic and structural properties of magnetically doped 3D topological insulator Bi2Se3. From muon spin relaxation measurements in zero…
Intense beam of metastable Muonium
G. Janka, B. Ohayon, Z. Burkley +10
Precision spectroscopy of the Muonium Lamb shift and fine structure requires a robust source of 2S Muonium. To date, the beam-foil technique is the only demonstrated method for cre…
Depth dependent spin dynamics of canonical spin glass films: A low-energy muon spin rotation study
E. Morenzoni, H. Luetkens, T. Prokscha +6
We have performed depth dependent muon spin rotation/relaxation studies of the dynamics of single layer films of {\it Au}Fe and {\it Cu}Mn spin glasses as a function of thickness a…
The Phase Diagram in Electron-Doped LCCO
H. Saadaoui, Z. Salman, H. Luetkens +8
Superconductors are a striking example of a quantum phenomenon in which electrons move coherently over macroscopic distances without scattering. The high-temperature superconductin…
Magnetism, superconductivity and coupling in cuprate heterostructures probed by low-energy muon-spin rotation
B. M. Wojek, E. Morenzoni, D. G. Eshchenko +8
We present a low-energy muon-spin-rotation study of the magnetic and superconducting properties of YBa2Cu3O7/PrBa2Cu3O7 trilayer and bilayer heterostructures. By determining the ma…
Depth-dependent study of time-reversal symmetry-breaking in the kagome superconductor VSb
J. N. Graham, C. Mielke, D. Das +21
The breaking of time-reversal symmetry (TRS) in the normal state of kagome superconductors VSb stands out as a significant feature. Yet the extent to which this effe…
Size and mass of Cooper pairs determined by low-energy SR and PNR
V. Kozhevnikov, A. Suter, H. Fritzsche +9
The Pippard coherence length (the size of a Cooper pair) in an extreme type-I superconductor was determined directly through high-resolution measurement of the nonlocal elec…
Science Case for the new High-Intensity Muon Beams HIMB at PSI
M. Aiba, A. Amato, A. Antognini +33
In April 2021, scientists active in muon physics met to discuss and work out the physics case for the new High-Intensity Muon Beams (HIMB) project at PSI that could deliver of orde…
Magnetic phase diagram of low-doped La{2-x}SrxCuO4 thin films studied by low-energy muon-spin rotation
E. Stilp, A. Suter, T. Prokscha +7
The magnetic phase diagram of La2-xSrxCuO4 thin-films grown on single-crystal LaSrAlO4 substrates has been determined by low-energy muon-spin rotation. The diagram shows the same f…
Cu-spin Correlation in the Electron-overdoped High-Tc Cuprate Thin Films of La_2-x_Ce_x_CuO_4_ Probed by Low-energy Muons
S. E. Park, Y. Kawai, A. Suter +7
We investigated the Cu-spin correlation in the overdoped regime of the electron-doped high-Tc cuprate thin films of La_2-x_Ce_x_CuO_4_, changing the reduction condition from muon s…
Superconductivity drives magnetism in delta-doped La2CuO4
A. Suter, G. Logvenov, A. V. Boris +7
The understanding of the interplay between different orders in a solid is a key challenge in highly correlated electronic systems. In real systems this is even more difficult since…
Drift time calibration of the ultra-low material budget GEM-based TPC for MIXE
X. Zhao, M. W. Heiss, F. Garcia +10
Muon-Induced X-ray Emission (MIXE) is a non-destructive analytical technique that leverages negative muons to probe elemental and isotopic compositions by detecting characteristic…
The Ultra-Low material budget GEM based TPC for tracking with VMM3a readout
F. Garcia, K. J. Flöthner, A. Amato +21
The Gaseous Electron Multiplier-based Time Projection Chamber (GEM-TPC) in TWIN configuration for particle tracking has been consolidated after extensive investigations in differen…
Muonium emission into vacuum from mesoporous thin films at cryogenic temperatures
A. Antognini, P. Crivelli, T. Prokscha +9
We report on Muonium (Mu) emission into vacuum following μ+ implantation in mesoporous thin SiO2 films. We obtain a yield of Mu into vacuum of (38\pm4)% at 250 K temperature and (…
Small sample measurements at the low energy muon facility of Paul Scherrer Institute
X. Ni, L. Zhou, M. M. Martins +3
The low energy muon spin rotation spectroscopy (LE-SR) is primarily used to investigate thin films, surfaces, and interfaces of materials, which has matured at the Paul Scherre…
Formation of hydrogen impurity states in silicon and insulators at low implantation energies
T. Prokscha, E. Morenzoni, D. G. Eshchenko +5
The formation of hydrogen-like muonium (Mu) has been studied as a function of implantation energy in intrinsic Si, thin films of condensed van der Waals gases (N2, Ne, Ar, Xe), fus…
Photo-induced persistent inversion of germanium in a 200-nm-deep surface region
T. Prokscha, K. H. Chow, E. Stilp +6
The controlled manipulation of the charge carrier concentration in nanometer thin layers is the basis of current semiconductor technology and of fundamental importance for device a…
Observation of non-exponential magnetic penetration profiles in the Meissner state - A manifestation of non-local effects in superconductors
A. Suter, E. Morenzoni, N. Garifianov +5
Implanting fully polarized low energy muons on the nanometer scale beneath the surface of a superconductor in the Meissner state enabled us to probe the evanescent magnetic field p…
Probing current-induced magnetic fields in Au|YIG heterostructure with low-energy muon spectroscopy
A. Aqeel, I. J. Vera-Marun, Z. Salman +4
We investigated the depth dependence of current-induced magnetic fields in a bilayer of a normal metal (Au) and a ferrimagnetic insulator (Yttrium Iron Garnet - YIG) by using low e…
Spatial confinement of muonium atoms
K. S. Khaw, A. Antognini, T. Prokscha +4
We report the achievement of spatial confinement of muonium atoms (the bound state of a positive muon and an electron). Muonium emitted into vacuum from mesoporous silica reflects…
A low energy muon spin rotation and point contact tunneling study of niobium films prepared for superconducting cavities
T. Junginger, S. Calatroni, A. Sublet +5
Point contact tunneling (PCT) and low energy muon spin rotation (LE-muSR) are used to probe, on the same samples, the surface superconducting properties of micrometer thick niobium…
Modifications of the Meissner screening profile in YBaCuO thin films by gold nanoparticles
E. Stilp, A. Suter, T. Prokscha +6
Adding Au nanoparticles to YBaCuO thin films leads to an increase of the superconducting transition temperature and the critical current density $j_{\r…
Superconductivity in La(1.56)Sr(0.44)CuO(4)/La(2)CuO(4) superlattices
A. Suter, E. Morenzoni, T. Prokscha +5
Superlattices of the repeated structure La(1.56)Sr(0.44)CuO(4)/La(2)CuO(4) (LSCO-LCO), where none of the constituents is superconducting, show a superconducting transition of T_c \…
Dimensionality Control of Electronic Phase Transitions in Nickel-Oxide Superlattices
A. V. Boris, Y. Matiks, E. Benckiser +15
The competition between collective quantum phases in materials with strongly correlated electrons depends sensitively on the dimensionality of the electron system, which is difficu…
Suppression of magnetic excitations near the surface of the topological Kondo insulator SmB6
P. K. Biswas, M. Legner, G. Balakrishnan +8
We present a detailed investigation of the temperature and depth dependence of the magnetic properties of 3D topological Kondo insulator SmB6 , in particular near its surface. We f…
Depth dependence of the ionization energy of shallow hydrogen states in ZnO and CdS
T. Prokscha, H. Luetkens, E. Morenzoni +5
The characteristics of shallow hydrogen-like muonium (Mu) states in nominally undoped ZnO and CdS (0001) crystals have been studied close to the surface at depths in the range of 1…
Correcting the Energy-Dependent Asymmetry in Low-Energy SR
G. Janka, Z. Salman, A. Suter +1
Low-energy SR (LE-SR) enables depth-resolved studies of magnetic and electronic properties from the surface into the near-surface region, but the measured transverse-field…
Intrinsic Ferromagnetism in the Diluted Magnetic Semiconductor Co:TiO
H. Saadaoui, X. Luo, Z. Salman +15
Here we present a study of magnetism in \CTO\ anatase films grown by pulsed laser deposition under a variety of oxygen partial pressures and deposition rates. Energy-dispersive spe…
Experimental Observation of Short-Range Magnetic Correlations in Amorphous NbO and TaO Thin Films
Y. V. Krasnikova, A. A. Murthy, D. Bafia +17
We use muon spin rotation/relaxation/resonance (SR) to investigate the magnetic properties of niobium pentoxide (NbO) and tantalum pentoxide (TaO) thin films. I…
Microscopic effects of Dy-doping in the topological insulator Bi2Te3
L. B. Duffy, N. -J. Steinke, J. A. Krieger +13
Magnetic doping with transition metal ions is the most widely used approach to break timereversal symmetry in a topological insulator, a prerequisite for unlocking the TIs exotic p…
Absence of broken time reversal symmetry beneath the surface of YBCO films
H. Saadaoui, Z. Salman, T. Prokscha +4
We report the results of a search for spontaneous magnetism due to a time reversal symmetry breaking phase in the superconducting state of (110)-oriented YBCO films, expected near…
Critical Fields of NbSn Prepared for Superconducting Cavities
S. Keckert, T. Junginger, T. Buck +10
NbSn is currently the most promising material other than niobium for future superconducting radiofrequency cavities. Critical fields above 120 mT in pulsed operation and about…
Coupling of Magnetic Phases at Nickelate Interfaces
C. DomÃnguez, J. Fowlie, A. B. Georgescu +9
In this work we present a model system built out of artificially layered materials, allowing us to understand the interrelation of magnetic phases with that of the metallic-insulat…
Improved upper limit on Muonium to Antimuonium Conversion
R. Abela, J. Bagaturia, W. Bertl +29
A new experiment has been set up at the Paul Scherrer Institut to search for muonium to antimuonium conversion. No event was found to fulfil the requested signature which consists…
Core-shell nanostructure in a Ge_0.9Mn_0.1 film from structural and magnetic measurements
P. Dalmas de Reotier, E. Prestat, P. Bayle-Guillemaud +8
We have characterized a film of Ge_0.9Mn_0.1 forming self-organized nanocolumns perpendicular to the Ge substrate with high resolution scanning transmission electron microscopy com…
Direct observation of non-local effects in a superconductor
A. Suter, E. Morenzoni, R. Khasanov +3
We have used the technique of low energy muon spin rotation to measure the local magnetic field profile B(z) beneath the surface of a lead film maintained in the Meissner state (z…
Measurement of the == transition in Muonium
G. Janka, B. Ohayon, I. Cortinovis +9
Muons are puzzling physicists since their discovery when they were first thought to be the meson predicted by Yukawa to mediate the strong force. The recent results at Fermilab on…
Transverse field muon-spin rotation measurement of the topological anomaly in a thin film of MnSi
T. Lancaster, F. Xiao, Z. Salman +9
We present the results of transverse-field muon-spin rotation measurements on an epitaxially grown 40 nm-thick film of MnSi on Si(111) in the region of the field-temperature phase…
Strong Meissner screening change in superconducting radio frequency cavities due to mild baking
A. Romanenko, A. Grassellino, F. Barkov +3
We investigate "hot" regions with anomalous high field dissipation in bulk niobium superconducting radio frequency cavities for particle accelerators by using low energy muon spin…
Precision measurement of the Lamb shift in Muonium
B. Ohayon, G. Janka, I. Cortinovis +10
We report a new measurement of the Lamb shift in Muonium using microwave spectroscopy. Our result of MHz comprises an order of…