178 citations
Counting papers with at most 25 authors, so collaboration author lists do not stand in for the people here.
- University of CopenhagenDK17 papers
- Technical University of DenmarkDK13 papers
- Statistics DenmarkDK7 papers
- Delft University of TechnologyNL3 papers
- Indiana UniversityUS3 papers
- Indiana University BloomingtonUS3 papers
- Aarhus UniversityDK2 papers
- Ben-Gurion University of the NegevIL2 papers
- Centre National de la Recherche ScientifiqueFR2 papers
- Chalmers University of TechnologySE2 papers
- DHIDK2 papers
- Laboratoire Temps EspaceFR2 papers
46 papers
Gate-tunable Superconductivity in Hybrid InSb-Pb Nanowires
Yan Chen, David van Driel, Charalampos Lampadaris +7
We present a report on hybrid InSb-Pb nanowires that combine high spin-orbit coupling with a high critical field and a large superconducting gap. Material characterization indicate…
Lower-temperature fabrication of airbridges by grayscale lithography to increase yield of nanowire transmons in circuit QED quantum processors
T. Stavenga, L. DiCarlo
Quantum hardware based on circuit quantum electrodynamics makes extensive use of airbridges to suppress unwanted modes of wave propagation in coplanar-waveguide transmission lines.…
Revisiting superconductivity in the extended one-band Hubbard model: pairing via spin and charge fluctuations
Mercè Roig, Astrid T. Rømer, P. J. Hirschfeld +1
The leading superconducting instabilities of the two-dimensional extended repulsive one-band Hubbard model within spin-fluctuation pairing theory depend sensitively on electron den…
Gradual emergence of superconductivity in underdoped LSCO
Ana-Elena Tutueanu, Machteld E. Kamminga, Tim B. Tejsner +13
We present triple-axis neutron scattering studies of low-energy magnetic fluctuations in strongly underdoped LaSrCuO with , and , providing…
Heat capacity double transitions in time-reversal symmetry broken superconductors
Henrik S. Røising, Glenn Wagner, Mercè Roig +2
Standard superconductors display a ubiquitous discontinuous jump in the electronic specific heat at the critical superconducting transition temperature. In a growing class of uncon…
Superconductivity from repulsive interactions on the kagome lattice
Astrid T. Rømer, Shinibali Bhattacharyya, Roser Valentí +2
The discovery of superconductivity in layered vanadium-based kagome metals VSb (: K, Rb, Cs) has added a new family of materials to the growing class of possible unco…
Photon assisted tunneling of high order multiple Andreev reflections in epitaxial nanowire Josephson junctions
Damon J. Carrad, Lukas Stampfer, Dags Olsteins +4
Semiconductor/superconductor hybrids exhibit a range of phenomena that can be exploited for the study of novel physics and the development of new technologies. Understanding the or…
Crystal Symmetry of Stripe Ordered La1.88Sr0.12CuO4
Ruggero Frison, Julia Kuespert, Qisi Wang +12
We present a combined x-ray and neutron diffraction study of the stripe ordered superconductor \lscox{0.12}. The average crystal structure is consistent with the orthorhombic $Bmab…
Round-robin differential phase-time-shifting protocol for quantum key distribution: theory and experiment
Kai Wang, Ilaria Vagniluca, Jie Zhang +4
Quantum key distribution (QKD) allows the establishment of common cryptographic keys among distant parties. Many of the QKD protocols that were introduced in the past involve the c…
Measurement and simulation of atomic motion in nanoscale optical trapping potentials
Signe B. Markussen, Jürgen Appel, Christoffer Østfeldt +3
Atoms trapped in the evanescent field around a nanofiber experience strong coupling to the light guided in the fiber mode. However, due to the intrinsically strong positional depen…
Continuous-wave coherent Raman spectroscopy for improving the accuracy of Raman shifts
Hugo Kerdoncuff, Mikael Lassen, Jan C. Petersen
Raman spectroscopy is an appealing technique that probes molecular vibrations in a wide variety of materials with virtually no sample preparation. However, accurate and reliable Ra…
Simple and robust speckle detection method for fire and heat detection in harsh environments
Charles N. Christensen, Yevgen Zainchkovskyy, Salvador Barrera-Figueroa +8
Standard laser based fire detection systems are often based on measuring variation of optical signal amplitude. However, mechanical noise interference and loss from dust and steam…
Versatile photoacoustic spectrometer based on a mid-infrared pulsed optical parametric oscillator
Laurent Lamard, David Balslev-Harder, Andre Peremans +2
We demonstrate the usefulness of a nanosecond pulsed single-mode mid-infrared (MIR) optical parametric oscillator (OPO) for Photoacoustic (PA) spectroscopic measurements. The maxim…
Temperature dependence of an Efimov resonance in
Lars J. Wacker, Nils B. Jørgensen, Kristoffer T. Skalmstang +3
Ultracold atomic gases are an important testing ground for understanding few-body physics. In particular, these systems enable a detailed study of the Efimov effect. We use ultraco…
Designing and experimental verification of a photoacoustic flow sensor using computational fluid dynamics
Mikael Lassen, David Balslev-Harder, Anders Brusch +3
A photoacoustic (PA) sensor for fast and real-time gas sensing is demonstrated. The PA sensor is a standalone system controlled by a Field-Programmable Gate Array (FPGA). The PA ce…
Time-of-flight expansion of binary Bose-Einstein condensates at finite temperature
Kean Loon Lee, Nils B. Jørgensen, Lars J. Wacker +4
Ultracold quantum gases provide a unique setting for studying and understanding the properties of interacting quantum systems. Here, we investigate a multi-component system of $^{8…
All-Optical Detection of Acoustic Pressure Waves with applications in Photo-Acoustic Spectroscopy
Philip G. Westergaard, Mikael Lassen
An all-optical detection method for the detection of acoustic pressure waves is demonstrated. The detection system is based on a stripped (bare) single-mode fiber. The fiber vibrat…
Off-axis QEPAS using a pulsed nanosecond Mid-Infrared Optical Parametric Oscillator
Mikael Lassen, Laurent Lamard, Yuyang Feng +2
A trace gas sensor, based on quartz-enhanced photoacoustic spectroscopy (QEPAS), consisting of two acoustically coupled micro-resonators (mR) with an off-axis 20 kHz quartz tuning…
Raman spectroscopy and electrical properties of InAs nanowires with local oxidation enabled by substrate micro-trenches and laser irradiation
R. Tanta, M. H. Madsen, Z. Liao +4
The thermal gradient along indium-arsenide nanowires was engineered by a combination of fabricated micro- trenches in the supporting substrate and focused laser irradiation. This a…
Alignment free characterization of 2D gratings
Morten Hannibal Madsen, Pierre Boher, Poul-Erik Hansen +1
Fast characterization of 2-dimensional gratings is demonstrated using a Fourier lens optical system and a differential optimization algorithm. It is shown that both the grating spe…
Imaging Scatterometry
Morten Hannibal Madsen, Poul-Erik Hansen
We present an optical metrology system for characterization of topography of micro/nano-structures on a surface or embedded in a semi-transparent material. Based on the principles…
Non-linear Spectroscopy of Sr Atoms in an Optical Cavity for Laser Stabilization
Bjarke T. R. Christensen, Martin R. Henriksen, Stefan A. Schäffer +4
We study the non-linear interaction of a cold sample of strontium-88 atoms coupled to a single mode of a low finesse optical cavity in the so-called bad cavity limit and investigat…
Differential high-resolution stimulated CW Raman spectroscopy of hydrogen in a hollow-core fiber
Philip G. Westergaard, Mikael Lassen, Jan C. Petersen
We demonstrate sensitive high-resolution stimulated Raman measurements of hydrogen using a hollow-core photonic crystal fiber (HC-PCF). The Raman transition is pumped by a narrow l…
Fast Characterization of Moving Samples with Nano-Textured Surfaces
Morten Hannibal Madsen, Poul-Erik Hansen, Maksim Zalkovskij +2
We characterize nano-textured surfaces by optical diffraction techniques using an adapted commercial light microscope with two detectors, a CCD camera and a spectrometer. The acqui…