Article
Materials Science, Multidisciplinary
H. Hijazi, D. Paget, G. Monier, G. Gregoire, J. Leymarie, E. Gil, F. Cadiz, C. Robert-Goumet, Y. Andre
Summary: Despite the expected difficulties due to high doping levels, it was found that charge and spin transport are achievable in n-type metallic GaAs nanowires, with the potential for long-distance spin transport. This was demonstrated through spatially and spectrally resolved investigations of luminescence intensity and circular polarization under laser excitation.
Article
Multidisciplinary Sciences
Peter Millington-Hotze, Santanu Manna, Saimon F. Covre da Silva, Armando Rastelli, Evgeny A. Chekhovich
Summary: The spin diffusion in inhomogeneously polarized many-body systems, such as nuclear spin lattices, is described classically by the spin diffusion concept. In this study, the authors directly observed spin diffusion in a single GaAs/AlGaAs quantum dot through oscillatory spin relaxation dynamics and found that electron spin accelerates nuclear spin relaxation, challenging the previously proposed Knight-field-gradient diffusion barrier concept. The findings have significant implications for understanding nuclear spin diffusion in quantum dots.
NATURE COMMUNICATIONS
(2023)
Article
Physics, Multidisciplinary
Zhong Shi, Qing Xi, Junxue Li, Yufei Li, Mohammed Aldosary, Yadong Xu, Jun Zhou, Shi-Ming Zhou, Jing Shi
Summary: The spin Seebeck effect (SSE) signal of magnon polarons in bulk-Y3Fe5O12 (YIG)/Pt heterostructures shows a transition from a dip to a peak as temperature increases, attributed to the rapid rise of the four-magnon scattering rate. This analysis offers important insights into the microscopic origin of hybridized excitations and the overall temperature dependence of SSE anomalies.
PHYSICAL REVIEW LETTERS
(2021)
Article
Physics, Applied
S. Anghel, A. V. Poshakinskiy, K. Schiller, G. Yusa, T. Mano, T. Noda, M. Betz
Summary: This study investigates the correlation between spin diffusion, spin lifetime, and electron density in low-dimensional GaAs semiconductors. It reveals that the variation in the scattering rate with electron density is more important than fulfilling the persistent spin helix condition for achieving the longest spin lifetime. The experiment shows that the longest spin lifetime occurs at the transition from Boltzmann to Fermi-Dirac statistics for electron density.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Physics, Condensed Matter
A. Mohajerani, Z. Faraei, S. A. Jafari
Summary: The spin lattice relaxation rate in 3D tilted cone Weyl semimetals was investigated, showing a unique behavior influenced by the tilt parameter. The strong enhancement of relaxation rates for zeta less than or similar to 1 is attributed to new hyperfine interactions arising from the tilt itself. Extracting an effective density of states reveals a relation to the underlying spacetime structure, showcasing a manifestation in TCWSMs.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2021)
Article
Physics, Applied
Bo Wang, Gaoshuai Wei, Jianing Chen, Li Wang
Summary: This study investigates ultrafast spin polarization in semi-insulating GaAs using terahertz time-domain spectroscopy. The results demonstrate that the transmitted and reflected terahertz signals exhibit different dynamic evolutions under the excitation of different polarization laser pulses, indicating the generation and relaxation process of spin-polarized electrons.
APPLIED PHYSICS LETTERS
(2022)
Article
Materials Science, Multidisciplinary
A. J. Wright, M. J. Erickson, D. Bromley, P. A. Crowell, C. Leighton, L. O'Brien
Summary: By correlating spin transport parameters with material, temperature, and field dependencies, the origin of unexpected field enhancement in certain ferromagnet/normal metal pairings in NLSVs has been identified as field quenching of magnetic impurity scattering. This effect was confirmed by agreement with field-dependent Kondo theory. The findings not only address a long-standing mystery, but also highlight a potential systematic underestimation of spin transport parameters, providing a simple means to isolate and quantify this additional relaxation mechanism.
Article
Multidisciplinary Sciences
Quentin Stern, Samuel Francois Cousin, Frederic Mentink-Vigier, Arthur Cesar Pinon, Stuart James Elliott, Olivier Cala, Sami Jannin
Summary: Dynamic nuclear polarization is a widely used tool for enhancing the sensitivity of nuclear magnetic resonance spectroscopy and imaging, but its practical applicability is limited by the spin diffusion barrier, which hinders efficient polarization transfer between highly polarized nuclei and bulk nuclei.
Article
Optics
Hui Ma, Yaojie Zhu, Yonghai Chen, Chongyun Jiang
Summary: In this study, we investigate the optical tuning of Rashba and Dresselhaus spin-orbit coupling (SOC) through monitoring the spin-galvanic effect (SGE) in a GaAs/Al0.3Ga0.7As two dimensional electron gas. The experimental results reveal different tunabilities of Rashba and Dresselhaus-related SGE currents, and the ratio of their coefficients decreases with the power of the control light, indicating the formation of the inverse persistent spin helix state. Phenomenological and microscopic analysis shows that the Rashba SOC exhibits greater optical tunability compared to the Dresselhaus SOC.
Article
Materials Science, Multidisciplinary
Q-P Ding, C. Dissanayake, Santanu Pakhira, W. J. Newsome, F. Uribe-Romo, D. C. Johnston, Y. Nakajima, Y. Furukawa
Summary: The results show that the Cu spin coupling in the three-dimensional hyperhoneycomb lattice compound CCCO has an average antiferromagnetic exchange coupling value of about 50 K, with Cu spin fluctuations slowing down at low temperatures exhibiting thermally activated behavior.
Article
Materials Science, Multidisciplinary
Victoria L. Karner, Aris Chatzichristos, David L. Cortie, Derek Fujimoto, Robert F. Kiefl, C. D. Philip Levy, Ruohong Li, Ryan M. L. McFadden, Gerald D. Morris, Matthew R. Pearson, Eva Benckiser, Alexander V. Boris, Georg Cristiani, Gennady Logvenov, Bernhard Keimer, W. Andrew MacFarlane
Summary: Using ion-implanted Li-8 beta-detected NMR, the study investigated the evolution of the correlated metallic state of LaNiO3 in LaNiO3/LaAlO3 superlattices as a function of bilayer thickness, revealing different relaxation components with varying temperature dependence. The metallic character of the slow relaxing component is weakly affected by the LaNiO3 thickness, while the fast component is more sensitive, showing opposite temperature dependence in the thinnest, most magnetic samples. This bipartite relaxation is discussed in terms of electronic phase separation.
Article
Physics, Applied
Oksana Chubenko, Siddharth Karkare, Dimitre A. Dimitrov, Jai Kwan Bae, Luca Cultrera, Ivan Bazarov, Andrei Afanasev
Summary: The anticorrelation between quantum efficiency (QE) and electron spin polarization (ESP) in p-doped GaAs is studied using a Monte Carlo approach, showing that the behavior can be explained by bulk relaxation mechanisms and the time electrons spend in the material.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Materials Science, Multidisciplinary
P. Sterin, L. Abaspour, J. G. Lonnemann, E. P. Rugeramigabo, J. Huebner, M. Oestreich
Summary: We present a detailed study of the temperature-dependent electron spin relaxation rate in n-type bulk GaAs and observe the longest spin relaxation time slightly below the metal-to-insulator transition at a finite temperature. This phenomenon results from the delicate interplay of hyperfine interaction, variable range hopping, and the Dyakonov-Perel mechanism.
Article
Materials Science, Multidisciplinary
I. A. Kokurin
Summary: Understanding the subband spectrum and wave functions of holes in III-V semiconductor nanowires is crucial for current applications. Previous studies have simplified the calculation of hole subbands, neglecting important features such as the real nanowire cross section shape and crystal orientation. In this study, these features are taken into account to calculate the subbands in GaAs nanowires. The results show that the lack of an inversion center significantly affects the subband spectrum and wave functions.
Article
Materials Science, Multidisciplinary
F. L. Pratt, F. Lang, W. Steinhardt, S. Haravifard, S. J. Blundell
Summary: Electron spin dynamics in the triangular-lattice quantum spin-liquid candidate YbZnGaO4 was investigated, revealing no evidence for freezing or ordering of the Yb spins. The muon spin relaxation rate can be decomposed into two contributions, one dependent on longitudinal magnetic field and the other independent of field. The spin-diffusion rate follows the expected form for two-dimensional diffusion of mobile spin excitations, and reduces significantly in the low temperature quantum regime, attributed to the effect of quantum entanglement. Comparison with theory suggests that the nodal spin-liquid model U1A11 provides better agreement with experimental data.
Article
Physics, Applied
Simon Geyer, Leon C. Camenzind, Lukas Czornomaz, Veeresh Deshpande, Andreas Fuhrer, Richard J. Warburton, Dominik M. Zumbuhl, Andreas V. Kuhlmann
Summary: Silicon quantum dot spin qubits have great potential for application in large-scale quantum circuits, but additional gates add to device complexity. By demonstrating the scalable integration of a multilayer gate stack in silicon quantum dot devices using self-alignment, the possibility of fast, all-electrical qubit control in the future is paved.
APPLIED PHYSICS LETTERS
(2021)
Article
Instruments & Instrumentation
M. Mergenthaler, S. Paredes, P. Mueller, C. Mueller, S. Filipp, M. Sandberg, J. B. Hertzberg, V. P. Adiga, M. Brink, A. Fuhrer
Summary: An ultra-high vacuum (UHV) package for superconducting qubit chips or other surface sensitive quantum devices is described, including the loading procedure, treatment capabilities, and measurement results. The package retains vacuum during transfer to cryogenic temperatures and has been shown to improve the performance of flux tunable qubits.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2021)
Article
Multidisciplinary Sciences
M. F. Ritter, A. Fuhrer, D. Z. Haxell, S. Hart, P. Gumann, H. Riel, F. Nichele
Summary: Recent experiments suggest that superconductivity in metallic nanowires can be controlled by applying electric fields, with critical currents being tuned and eventually suppressed by small gate voltages. However, the mechanism behind critical current suppression remains controversial, with some proposing tunneling of high-energy electrons as a key factor. The onset of critical current suppression below 100fA gate currents presents challenges in typical experiments.
NATURE COMMUNICATIONS
(2021)
Review
Physics, Multidisciplinary
M. Pechal, G. Salis, M. Ganzhorn, D. J. Egger, M. Werninghaus, S. Filipp
Summary: This paper discusses the control and measurement capabilities of hidden qubits in certain physical architectures where direct addressability is lacking. It demonstrates full control and measurement capabilities in a superconducting two-qubit device with local single-qubit control and iSWAP and controlled-phase two-qubit interactions enabled by a tunable coupler. The iterative tune-up process for characterizing gate sets used for quantum process tomography and evaluating gate fidelities is also introduced.
Article
Quantum Science & Technology
M. Mergenthaler, C. Muller, M. Ganzhorn, S. Paredes, P. Muller, G. Salis, V. P. Adiga, M. Brink, M. Sandberg, J. B. Hertzberg, S. Filipp, A. Fuhrer
Summary: The study shows that Ne ion bombardment reduces the relaxation rate of qubits, while SF6 ion bombardment can adjust qubit frequencies; UV-light and NH3 treatments are beneficial for removing magnetic adsorbates from chip surfaces; these treatments help improve the performance of quantum processors.
NPJ QUANTUM INFORMATION
(2021)
Article
Engineering, Electrical & Electronic
Leon C. Camenzind, Simon Geyer, Andreas Fuhrer, Richard J. Warburton, Dominik M. Zumbuehl, Andreas Kuhlmann
Summary: The greatest challenge in quantum computing is achieving scalability. However, silicon fin field-effect transistors can host spin qubits operating above 4 K, potentially enabling the scaling and development of quantum computing systems.
NATURE ELECTRONICS
(2022)
Article
Engineering, Electrical & Electronic
M. F. Ritter, N. Crescini, D. Z. Haxell, M. Hinderling, H. Riel, C. Bruder, A. Fuhrer, F. Nichele
Summary: Recent experiments have shown that superconductivity in metallic nanowires can be suppressed by applying a moderate gate voltage. This suppression is not due to the presence of electric fields at the nanowire surface, but rather requires the flow of high-energy electrons. The decay of these electrons into phonons, which propagate through the substrate and affect superconductivity, is the key factor in the suppression of superconductivity in nanowires.
NATURE ELECTRONICS
(2022)
Review
Physics, Applied
Alexey Kimel, Anatoly Zvezdin, Sangeeta Sharma, Samuel Shallcross, Nuno de Sousa, Antonio Garcia-Martin, Georgeta Salvan, Jaroslav Hamrle, Ondrej Stejskal, Jeffrey McCord, Silvia Tacchi, Giovanni Carlotti, Pietro Gambardella, Gian Salis, Markus Muenzenberg, Martin Schultze, Vasily Temnov, Igor Bychkov, Leonid N. Kotov, Nicolo Maccaferri, Daria Ignatyeva, Vladimir Belotelov, Claire Donnelly, Aurelio Hierro Rodriguez, Iwao Matsuda, Thierry Ruchon, Mauro Fanciulli, Maurizio Sacchi, Chunhui Rita Du, Hailong Wang, N. Peter Armitage, Mathias Schubert, Vanya Darakchieva, Bilu Liu, Ziyang Huang, Baofu Ding, Andreas Berger, Paolo Vavassori
Summary: This article provides a comprehensive overview of recent developments, advances, and emerging research directions in the field of magneto-optics. It covers various applications of magneto-optical effects in different materials and spectral ranges. It serves as an important reference for emerging research directions in modern magneto-optics.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2022)
Article
Chemistry, Multidisciplinary
Sofieke C. ten Kate, Markus F. Ritter, Andreas Fuhrer, Jason Jung, Sander G. Schellingerhout, Erik P. A. M. Bakkers, Heike Riel, Fabrizio Nichele
Summary: This study characterizes electron quantum dots in PbTe nanowires grown on InP, revealing unique electronic properties. The charge stability diagram shows large even???odd spacing and small charging energies, with Kondo peaks observed in odd Coulomb diamonds. By studying the energy levels and splitting under finite magnetic fields, highly anisotropic g-factor tensor and its dependence on electronic configuration are found, suggesting strong Rashba spin???orbit interaction in PbTe quantum dots.
Editorial Material
Nanoscience & Nanotechnology
Nico W. Hendrickx, Andreas Fuhrer
NATURE NANOTECHNOLOGY
(2022)
Article
Physics, Applied
Michele Aldeghi, Rolf Allenspach, Gian Salis
Summary: On-chip micromagnets are used for electrically controlled quantum gates on electron spin qubits. A design is presented for driving spin qubits arranged in a linear chain and strongly confined in directions lateral to the chain. The concept is validated using micromagnetic simulations and spin-polarized scanning electron microscopy of Fe nanomagnets. The design meets several requirements for a scalable spin qubit design.
APPLIED PHYSICS LETTERS
(2023)
Article
Physics, Applied
Makoto Kohda, Takeshi Seki, Yasushi Yuminaka, Tetsuya Uemura, Keito Kikuchi, Gian Salis
Summary: This article discusses the differences between waves and particle properties, as well as their applications in data processing and storage. It introduces the information theory of wave-parallel computing and the fundamental properties needed for wave-based information carriers. The potential of electron spin waves and magnons as information carriers for processing and storage is examined. The interconversion among light helicity, electron spin waves, and magnons is also discussed.
APPLIED PHYSICS LETTERS
(2023)
Article
Physics, Multidisciplinary
Marek Pechal, Federico Roy, Samuel A. Wilkinson, Gian Salis, Max Werninghaus, Michael J. Hartmann, Stefan Filipp
Summary: This study demonstrates a controlled gate implemented in superconducting qubits, which generalizes classical perceptrons as the basic building block of quantum neural networks. Through tuning gate length, qubit coupling, and drive frequency, full control over the perceptron activation function, input weight, and bias is achieved. The gate performs a multiqubit entangling operation in a single step, requiring fewer gates than traditional decomposition.
PHYSICAL REVIEW RESEARCH
(2022)
Article
Materials Science, Multidisciplinary
Daisuke Iizasa, Asuka Aoki, Takahito Saito, Junsaku Nitta, Gian Salis, Makoto Kohda
Summary: This study investigates the spatiotemporal spin dynamics under spin-orbit interaction in a (001) GaAs two-dimensional electron gas using magneto-optical Kerr rotation microscopy. It was found that the induction of spin precession frequency nonlinearly depends on the diffusion velocity near the cancellation between spin-orbit field and external magnetic field, contrary to conventional expectations. This unexpected behavior is attributed to the enhancement of spin relaxation anisotropy by the electron velocity perpendicular to the diffused direction.
