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Normalization procedure for obtaining the local density of states from high-bias scanning tunneling spectroscopy

Rejali, R. (author), Farinacci, L.S.M. (author), Otte, A.F. (author)

Differential conductance spectroscopy performed in the high bias regime - in which the applied voltage exceeds the sample work function - is a suboptimal measure of the local density of states due to the effects of the changing tunnel barrier. Additionally, the large applied voltage oftentimes makes constant-height measurement experimentally...

journal article 2023

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Advances in Magnetics Roadmap on Spin-Wave Computing

Blanter, Y.M. (author), Carmiggelt, J.J. (author), Cotofana, S.D. (author), Hamdioui, S. (author), Nikitin, A. A. (author), Reimann, T. (author), Sharma, S. (author), van der Sar, T. (author), Zhang, X. (author)

Magnonics addresses the physical properties of spin waves and utilizes them for data processing. Scalability down to atomic dimensions, operation in the GHz-to-THz frequency range, utilization of nonlinear and nonreciprocal phenomena, and compatibility with CMOS are just a few of many advantages offered by magnons. Although magnonics is still...

journal article 2022

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Confined Vacuum Resonances as Artificial Atoms with Tunable Lifetime

Rejali, R. (author), Farinacci, L.S.M. (author), Coffey Blanco, D. (author), Broekhoven, R. (author), Gobeil, J. (author), Blanter, Y.M. (author), Otte, A.F. (author)

Atomically engineered artificial lattices are a useful tool for simulating complex quantum phenomena, but have so far been limited to the study of Hamiltonians where electron-electron interactions do not play a role. However, it is precisely the regime in which these interactions do matter where computational times lend simulations a critical...

journal article 2022

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On-chip distribution of quantum information using traveling phonons

Zivari, A. (author), Fiaschi, N. (author), Burgwal, Roel (author), Verhagen, Ewold (author), Stockill, Robert (author), Groeblacher, S. (author)

Distributing quantum entanglement on a chip is a crucial step toward realizing scalable quantum processors. Using traveling phonons-quantized guided mechanical wave packets-as a medium to transmit quantum states is now gaining substantial attention due to their small size and low propagation speed compared to other carriers, such as electrons...

journal article 2022

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Filtering and Imaging of Frequency-Degenerate Spin Waves Using Nanopositioning of a Single-Spin Sensor

Simon, B.G. (author), Kurdi, S. (author), Carmiggelt, J.J. (author), Borst, M. (author), Katan, A.J. (author), van der Sar, T. (author)

Nitrogen-vacancy (NV) magnetometry is a new technique for imaging spin waves in magnetic materials. It detects spin waves by their microwave magnetic stray fields, which decay evanescently on the scale of the spin-wavelength. Here, we use nanoscale control of a single-NV sensor as a wavelength filter to characterize frequency-degenerate spin...

journal article 2022

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Cloaked near-field probe for non-invasive near-field optical microscopy

Bernal Arango, F.A. (author), Alpeggiani, F. (author), Conteduca, Donato (author), Opheij, A. (author), Chen, Aobo (author), Abdelrahman, Mohamed I. (author), Krauss, Thomas F. (author), Alù, Andrea (author), Kuipers, L. (author)

Near-field scanning optical microscopy is a powerful technique for imaging below the diffraction limit, which has been extensively used in biomedical imaging and nanophotonics. However, when the electromagnetic fields under measurement are strongly confined, they can be heavily perturbed by the presence of the near-field probe itself. Here,...

journal article 2022

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Topological Protection in Radiative Photonic Crystal Cavities

Barczyk, R.T. (author), Parappurath, N. (author), Arora, S. (author), Bauer, T.A. (author), Kuipers, L. (author), Verhagen, E. (author)

We study the signatures of topological light confinement in the leakage radiation of two-dimensional topological photonic crystal cavities that feature the quantum spin Hall effect at telecom wavelengths. The mode profiles in real and momentum space are retrieved using far field imaging and Fourier spectropolarimetry. We examine the scaling...

conference paper 2022

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Revealing the nanogeometry of WS2 nanoflowersby polarization-resolved Raman spectroscopy

Komen, I. (author), van Heijst, S.E. (author), Caldarola, M. (author), Conesa Boj, S. (author), Kuipers, L. (author)

Recent studies of transition metal dichalcogenides (TMDs) have revealed exciting optical properties, such as stable excitons and chiral light–matter interactions. Chemical vapor deposition techniques provide a platform for the fabrication of nanostructures with diverse geometries, ranging from horizontal flakes to flower-like structures. Raman...

journal article 2022

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Breakdown of Spin-to-Helicity Locking at the Nanoscale in Topological Photonic Crystal Edge States

Arora, S. (author), Bauer, T.A. (author), Parappurath, N. (author), Barczyk, R.T. (author), Verhagen, E. (author), Kuipers, L. (author)

We measure the local near-field spin in topological edge state waveguides that emulate the quantum spin Hall effect. We reveal a highly structured spin density distribution that is not linked to a unique pseudospin value. From experimental near-field real-space maps and numerical calculations, we confirm that this local structure is essential...

journal article 2022

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Non-classical mechanical states guided in a phononic waveguide

Zivari, A. (author), Stockill, R.H.J. (author), Fiaschi, N. (author), Groeblacher, S. (author)

The ability to create, manipulate and detect non-classical states of light has been key for many recent achievements in quantum physics and for developing quantum technologies. Achieving the same level of control over phonons, the quanta of vibrations, could have a similar impact, in particular on the fields of quantum sensing and quantum...

journal article 2022

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Simultaneous Characterization of Two Ultrashort Optical Pulses at Different Frequencies Using a WS₂Monolayer

Noordam, Marcus L. (author), Hernandez Rueda, F.J. (author), Kuipers, L. (author)

The precise characterization of ultrashort laser pulses has been of interest to the scientific community for many years. Frequency-resolved optical gating (FROG) has been extensively used to retrieve the temporal and spectral field distributions of ultrashort laser pulses. In this work, we exploit the high, broad-band nonlinear optical...

journal article 2022

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Ultrafast scanning electron microscopy with sub-micrometer optical pump resolution

Garming, M.W.H. (author), Weppelman, I.G.C. (author), Lee, M. (author), Stavenga, T. (author), Hoogenboom, J.P. (author)

Ultrafast scanning electron microscopy images carrier dynamics and carrier induced surface voltages using a laser pump electron probe scheme, potentially surpassing all-optical techniques in probe resolution and surface sensitivity. Current implementations have left a four order of magnitude gap between optical pump and electron probe...

journal article 2022

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Electronic Properties and Phase Transition in the Kagome Metal Yb_0.5Co₃Ge₃

Wang, Y. (author), McCandless, Gregory T. (author), Wang, Xiaoping (author), Thanabalasingam, Kulatheepan (author), Wu, H. (author), Bouwmeester, D. (author), van der Zant, H.S.J. (author), Ali, M.N. (author), Chan, C.L. (author)

The Kagome lattice is an important fundamental structure in condensed matter physics for investigating the interplay of electron correlation, topology, and frustrated magnetism. Recent work on Kagome metals in the AV3Sb5 (A = K, Rb, and Cs) family has shown a multitude of correlation-driven distortions, including symmetry breaking charge...

journal article 2022

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Compact amorphous-silicon visible-light monitor integrated in silicon nitride waveguides

De Vita, Christian (author), Klitis, Charalambos (author), Codreanu, N. (author), Ferrari, Giorgio (author), Sorel, Marc (author), Melloni, Andrea (author), Morichetti, Francesco (author)

This work reports on the realization of an amorphous silicon visible-light detector integrated in Si3N4 waveguides. The device is very compact (< 40 μm), has a responsivity of about 10 mA/W and a sensitivity of -40 dBm.

conference paper 2022

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Einstein-Podolsky-Rosen entanglement and asymmetric steering between distant macroscopic mechanical and magnonic systems

Tan, Huatang (author), Li, J. (author)

We propose a deterministic scheme for establishing hybrid Einstein-Podolsky-Rosen (EPR) entanglement channel between a macroscopic mechanical oscillator and a magnon mode in a distant yttrium-iron-garnet (YIG) sphere across about 10 GHz of frequency difference. The system consists of a driven electromechanical cavity which is unidirectionally...

journal article 2021

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Radiationless anapole states in on-chip photonics

Díaz-Escobar, Evelyn (author), Bauer, T.A. (author), Pinilla-Cienfuegos, Elena (author), Barreda, Ángela I. (author), Griol, Amadeu (author), Kuipers, L. (author), Martínez, Alejandro (author)

High-index nanoparticles are known to support radiationless states called anapoles, where dipolar and toroidal moments interfere to inhibit scattering to the far field. In order to exploit the striking properties arising from these interference conditions in photonic integrated circuits, the particles must be driven in-plane via integrated...

journal article 2021

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Position-Controlled Fabrication of Vertically Aligned Mo/MoS₂ Core–Shell Nanopillar Arrays

Maduro, L.A. (author), Noordam, M.L. (author), Bolhuis, M. (author), Kuipers, L. (author), Conesa Boj, S.C. (author)

The fabrication of 2D materials, such as transition metal dichalcogenides (TMDs), in geometries beyond the standard platelet-like configuration exhibits significant challenges which severely limit the range of available morphologies. These challenges arise due to the anisotropic character of their bonding van der Waals out-of-plane while...

journal article 2021

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Directional Excitation of a High-Density Magnon Gas Using Coherently Driven Spin Waves

Simon, B.G. (author), Kurdi, S. (author), La, Helena (author), Bertelli, I. (author), Carmiggelt, J.J. (author), Ruf, M.T. (author), de Jong, N. (author), van den Berg, J.H. (author), Katan, A.J. (author), van der Sar, T. (author)

Controlling magnon densities in magnetic materials enables driving spin transport in magnonic devices. We demonstrate the creation of large, out-of-equilibrium magnon densities in a thin-film magnetic insulator via microwave excitation of coherent spin waves and subsequent multimagnon scattering. We image both the coherent spin waves and the...

journal article 2021

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Imaging Spin-Wave Damping Underneath Metals Using Electron Spins in Diamond

Bertelli, I. (author), Simon, B.G. (author), Yu, T. (author), Aarts, Jan (author), Bauer, G.E. (author), Blanter, Y.M. (author), van der Sar, T. (author)

Spin waves in magnetic insulators are low-damping signal carriers that can enable a new generation of spintronic devices. The excitation, control, and detection of spin waves by metal electrodes is crucial for interfacing these devices to electrical circuits. As such, it is important to understand metal-induced damping of spin-wave transport,...

journal article 2021

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Morphology-induced spectral modification of self-assembled WS₂pyramids

Komen, I. (author), van Heijst, S.E. (author), Conesa Boj, S.C. (author), Kuipers, L. (author)

Due to their intriguing optical properties, including stable and chiral excitons, two-dimensional transition metal dichalcogenides (2D-TMDs) hold the promise of applications in nanophotonics. Chemical vapor deposition (CVD) techniques offer a platform to fabricate and design nanostructures with diverse geometries. However, the more exotic the...

journal article 2021