Article
Nanoscience & Nanotechnology
Kristjan Ottar Klausen, Anna Sitek, Sigurdur I. Erlingsson, Andrei Manolescu
Summary: Flux-periodic oscillations of the superconducting gap in proximitized core-shell nanowires are investigated, comparing the periodicity of oscillations in the energy spectrum between cylindrical nanowires and nanowires with hexagonal and square cross-section geometries, while also considering the effects of Zeeman and Rashba spin-orbit interaction. A transition from h/e to h/2e periodicity is observed, depending on the chemical potential and corresponding to degeneracy points of the angular momentum quantum number. In the case of a thin shell of a square nanowire, solely h/e periodicity is found in the infinite wire spectrum, resulting from energy separation between the lowest groups of excited states.
Article
Materials Science, Multidisciplinary
Eric Kleinherbers, Alexander Schuenemann, Juergen Koenig
Summary: We study the full counting statistics of electron transport through a Majorana single-charge transistor. At low bias voltage, the transport is dominated by the Josephson-Majorana cycle, involving normal and anomalous single-charge and Josephson tunneling. The factorial cumulants of the full counting statistics reveal the correlated nature of the charge transfers in this cycle. Additionally, we predict a topological transition in the full counting statistics, whereby the transfer of Cooper pairs changes from a perfect Poissonian distribution to a correlated switching between two distinct fermion parity states as the Josephson coupling increases.
Article
Multidisciplinary Sciences
Alexandros Vekris, Juan Carlos Estrada Saldana, Joeri de Bruijckere, Sara Loric, Thomas Kanne, Mikelis Marnauza, Dags Olsteins, Jesper Nygard, Kasper Grove-Rasmussen
Summary: Little-Parks oscillations in a hollow superconducting cylinder are typically symmetric, but can become asymmetric when a small misalignment of the applied parallel field with respect to the axis of the nanowires occurs. This asymmetry is observed in both destructive and non-destructive regimes, with superconductivity either destroyed or depressed but not fully destroyed at certain flux values.
SCIENTIFIC REPORTS
(2021)
Article
Chemistry, Multidisciplinary
Yong Sun, Ziheng Lin, Fei Tian, Bo Sun, Xiaobin Zou, Chengxin Wang
Summary: This study demonstrates the design of silicon-based Mn5Si3@SiO2 nanocables through structure engineering, exhibiting diverse mechanical behaviors under different external conditions, including simplex elasticity, plasticity, and viscoelasticity. These tunable performances originate from the synergetic effects between the core and shell components, optimizing internal stress distribution and the dislocation evolution mechanism. The findings are significant for nanowire mechanical design and the expansion of strain-regulated three-dimensional multifunctional nanosystems.
Article
Physics, Multidisciplinary
Jing He, Xiao-Qi Wang, Lian-Lian Zhang, Tong-Tong Xu, W. J. Gong
Summary: In this study, the impact of a quantum dot on Majorana-induced Andreev reflection was investigated. It was found that the quantum dot can have variable effects on the zero-bias conductance, suppressing reflection when non-superconducting with zero-energy level, and becoming dominant for the Majorana nonzero mode, including the zero-bias result.
Article
Chemistry, Multidisciplinary
Jae-Joon Kim, Min Seok Park, Kyoung Seok Lee, Sang Hyun Joo, Jung Hoon Yoo, Dilip Bhoi, Byeong Hun Min, Kee Hoon Kim, Jinho Lee
Summary: In this study, the electronic structure of CLFA112 crystals was investigated at the atomic scale using low-temperature scanning tunneling microscopy (STM). Four different types of surface reconstructions were observed on CLFA112 crystals, and a clear superconducting gap was observed only at certain crevices on the surface. The FeAs layer exhibited a dispersing nematic modulation, and peculiar zero-bias conductance peaks were observed in the arsenic chain layer along with the influence of La dopants.
Article
Physics, Multidisciplinary
Matthias Thamm, Bernd Rosenow
Summary: As the complexity of quantum systems increases, automating expensive tuning becomes more worthwhile. In this study, we investigated the use of machine learning and the covariance matrix adaptation evolution strategy algorithm to tune gate arrays for Majorana wires with strong disorder. We found that the algorithm efficiently improved topological signatures, learned disorder profiles, and eliminated disorder effects. For instance, optimization of gate voltages with only 20 gates allowed the complete recovery of Majorana zero modes destroyed by disorder.
PHYSICAL REVIEW LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Pablo San-Jose, Carlos Paya, C. M. Marcus, S. Vaitiekenas, Elsa Prada
Summary: Full-shell nanowires are hybrid nanostructures with a semiconducting core and a superconducting shell. We theoretically show that these nanowires can exhibit CdGM analogs, which are subgap states induced by the shell. The skewness of the CdGM analogs inside nonzero LP lobes can be used to extract microscopic information.
Article
Physics, Multidisciplinary
Milad Norouzi, Jamileh Seyed-Yazdi
Summary: This study investigated the effect of slip angle on superconducting quasi-one-dimensional carbon structures, finding that slip angle plays an interesting role similar to a mixed superconducting state by creating a mass-like gap in the electron-hole excitation spectrum. The transport properties in the superconducting linear carbon chain were also examined within the framework of the Dirac-Bogoliubov-de Gennes formalism, where the superconductor gap was considered to be a spin-singlet and spin-triplet superconducting state.
Article
Materials Science, Multidisciplinary
Gregor Gurski, Henning Kirchberg, Peter Nalbach, Michael Thorwart
Summary: We propose a quantum-mechanical model to calculate the current through a single molecular junction immersed in a solvent and surrounded by a thin shell of bound water under an applied ac voltage. The charge current through the molecular junction under an ac voltage in the sequential tunneling regime is determined using a quantum master equation solved by a real-time diagrammatic technique. The findings show that the current is highly sensitive to both the hydration shell thickness as well as the volume fraction of the solvent mixture, suggesting potential applications in shell and concentration sensors on the molecular scale.
Article
Chemistry, Multidisciplinary
Xinming Zhuang, Zixu Sa, Jie Zhang, Mingxu Wang, Mingsheng Xu, Fengjing Liu, Kepeng Song, Tao He, Feng Chen, Zai-xing Yang
Summary: High-performance GaSb nanowire field-effect transistors (FETs) with excellent bias-stress stability and synaptic behaviors are achieved by utilizing native GaOx shells through in-situ thermal annealing. The native oxide shell provides enhanced stability and charge retention capability for synaptic behaviors.
Article
Biochemistry & Molecular Biology
Javier Garcia, Ruth Gutierrez, Ana S. Gonzalez, Ana I. Jimenez-Ramirez, Yolanda Alvarez, Victor Vega, Heiko Reith, Karin Leistner, Carlos Luna, Kornelius Nielsch, Victor M. Prida
Summary: Tuning and controlling the magnetic properties of nanomaterials is crucial for implementing new technologies. In this study, core/shell Ni@(NiO, Ni(OH)2) nanowire arrays were fabricated using an electrochemical approach, and their magnetic properties were characterized. The results showed surface oxidation-induced magnetic hardening in the nanowires and an increasing exchange bias effect at low temperatures.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2023)
Article
Chemistry, Applied
Pier Giorgio Schiavi, Pietro Altimari, Robertino Zanoni, Francesca Pagnanelli
Summary: A novel process is reported for producing an asymmetric supercapacitor through complete recycling of end-of-life lithium ion batteries. The recovered electrodic powder and dissolved metals were used to produce nanowires battery-type electrodes, resulting in a specific capacitance of 42 F g(-1) and a maximum energy density of approximately 9 Wh kg(-1) when assembled with graphite as negative electrodes.
JOURNAL OF ENERGY CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Julien Bosch, Pierre-Marie Coulon, Sebastien Chenot, Marc Portail, Christophe Durand, Maria Tchernycheva, Philip A. Shields, Jesus Zuniga-Perez, Blandine Alloing
Summary: This paper proposes three different strategies, chemical, physical, or thermal etching, to remove the SiGaxNy layer on the sidewalls of GaN core-shell wires, thereby improving their optical quality. Chemical etching with H3PO4 enhances the emissive coverage and luminescence intensity, while removing deep-defect emissions from the high growth temperature.
CRYSTAL GROWTH & DESIGN
(2022)
Article
Physics, Fluids & Plasmas
Fan Zhang, Jiayin Gu, H. T. Quan
Summary: In this study, we analytically calculate the cumulant generating function of energy and particle transport in an open one-dimensional Kitaev chain at finite temperature using the Keldysh technique. The joint distribution of particle and energy currents satisfies different fluctuation relations in different regions of the parameter space due to U(1) symmetry breaking and energy conservation. Additionally, we investigate the linear response behavior of the Kitaev chain within the framework of three-terminal systems, deriving expressions for the Seebeck coefficient and thermal conductance. Notably, we observe a pronounced peak in the thermal conductance near the phase transition point, consistent with previous predictions. Furthermore, we prove that the peak value saturates at half of the thermal conductance quantum for finite-length chains at the zero temperature limit.
Article
Physics, Applied
Filip K. Malinowski, Lin Han, Damaz de Jong, Ji-Yin Wang, Christian G. Prosko, Ghada Badawy, Sasa Gazibegovic, Yu Liu, Peter Krogstrup, Erik P. A. M. Bakkers, Leo P. Kouwenhoven, Jonne V. Koski
Summary: This article demonstrates the use of radio-frequency (rf) resonators to measure the capacitance of nanoscale semiconducting devices. The method is tested on InSb and InAs nanowires at different temperatures. Different implementations result in varying measurement sensitivity and noise levels. The research shows that this method can be applied in several areas, including capacitance measurement and field-effect mobility measurement.
PHYSICAL REVIEW APPLIED
(2022)
Article
Physics, Applied
Arno Bargerbos, Lukas Johannes Splitthoff, Marta Pita-Vidal, Jaap J. Wesdorp, Yu Liu, Peter Krogstrup, Leo P. Kouwenhoven, Christian Kraglund Andersen, Lukas Grunhaupt
Summary: Quantum error correction is crucial for achieving fault-tolerant quantum computing, but existing schemes assume uncorrelated errors in space and time. However, in superconducting qubits, ionizing radiation violates this assumption and leads to correlated errors. To mitigate this, adding large volumes of normal or superconducting metal to the device can decrease the phonon energy below the superconducting gap of the qubits. In experiments with a nanowire-based transmon qubit device, we found that with a lower superconducting gap material, there was 2-5 times less degradation in qubit lifetimes and the undesired qubit state population was also reduced. The effectiveness of this protection was not limited by the size of the superconducting gap in the added metal. These findings provide a promising foundation for protecting superconducting-qubit processors against correlated errors from ionizing radiation.
PHYSICAL REVIEW APPLIED
(2023)
Article
Chemistry, Multidisciplinary
Sabbir A. Khan, Sara Marti-Sanchez, Dags Olsteins, Charalampos Lampadaris, Damon James Carrad, Yu Liu, Judith Quinones, Maria Chiara Spadaro, Thomas Sand Jespersen, Peter Krogstrup, Jordi Arbiol
Summary: Hybrid semiconductor-superconductor nanowires are widely used for studying gate-tunable superconductivity and the emergence of topological behavior. The low dimensionality and crystal structure flexibility of these nanowires enable unique heterostructure growth and efficient material optimization, which are crucial for accurately constructing complex multicomponent quantum materials.
Article
Physics, Multidisciplinary
Marta Pita-Vidal, Arno Bargerbos, Rok Zitko, Lukas J. Splitthoff, Lukas Grunhaupt, Jaap J. Wesdorp, Yu Liu, Leo P. Kouwenhoven, Ramon Aguado, Bernard van Heck, Angela Kou, Christian Kraglund Andersen
Summary: Spin qubits in semiconductors are a promising platform for scalable quantum computing devices, but achieving multiqubit interactions over extended distances is challenging. Superconducting spin qubits encoded in Andreev levels provide an alternative with intrinsic spin-supercurrent coupling. This study demonstrates an electrostatically defined quantum dot Josephson junction with a spin-split doublet ground state, allowing for qubit manipulation and investigating the qubit performance using direct spin manipulation. Coupling the Andreev spin qubit with a superconducting transmon qubit shows strong coherent qubit-qubit coupling, a crucial step towards a hybrid architecture combining the advantages of both superconducting and semiconductor qubits.
Article
Multidisciplinary Sciences
Werner M. J. van Weerdenburg, Anand Kamlapure, Eirik Holm Fyhn, Xiaochun Huang, Niels P. E. van Mullekom, Manuel Steinbrecher, Peter Krogstrup, Jacob Linder, Alexander Ako Khajetoorians
Summary: We observe a threefold enhancement of the superconducting critical temperature and gap size in ultrathin epitaxial Al films on Si(111) approaching the 2D limit. We characterize the vortex structure using spatially resolved spectroscopy and find evidence of a paramagnetic Meissner effect originating from odd-frequency pairing contributions. These results highlight the influences of reduced dimensionality on a BCS superconductor and provide a platform for studying BCS superconductivity in large magnetic fields.
Article
Materials Science, Multidisciplinary
Rajib Batabyal, Steffen Zelzer, Alec P. Romagosa, Derek Dardzinski, Fabiano Corsetti, Noa Marom, Peter Krogstrup
Summary: The atomic structure of surfaces and interfaces affects the electronic quality and properties of quantum devices. In this study, the interplay between surface and confined bulk subband states was examined on an InAs(111)A-(2 x 2) reconstructed surface with crystal defects using low-temperature scanning tunneling microscopy and spectroscopy. Two-dimensional quantized subband states resulting from the confined potential imposed by the downward bending of the conduction band edge were measured. Surface Bloch states within the confined bulk band gap projected on the surface spectrum were also observed.
PHYSICAL REVIEW MATERIALS
(2023)
Article
Physics, Applied
Yan Chen, David van Driel, Charalampos Lampadaris, Sabbir A. Khan, Khalifah Alattallah, Lunjie Zeng, Eva Olsson, Tom Dvir, Peter Krogstrup, Yu Liu
Summary: We present a report on hybrid InSb-Pb nanowires that exhibit high spin-orbit coupling, high critical field, and large superconducting gap. Material characterization confirms the high crystal quality of the Pb layer on the nanowire side facets. The hybrid nanowires show hard induced superconducting gaps and gate-tunable supercurrent, highlighting their potential for various applications in hybrid quantum transport devices.
APPLIED PHYSICS LETTERS
(2023)
Article
Physics, Multidisciplinary
Arno Bargerbos, Marta Pita-Vidal, Rok Zitko, Lukas J. Splitthoff, Lukas Grunhaupt, Jaap J. Wesdorp, Yu Liu, Leo P. Kouwenhoven, Ramon Aguado, Christian Kraglund Andersen, Angela Kou, Bernard van Heck
Summary: We performed spectroscopy of a quantum dot Josephson junction using a hybrid superconductor-semiconductor transmon device. The spin-orbit coupling in the device allowed us to observe two flux-sensitive branches in the transmon spectrum. A finite magnetic field caused a shift in the energy of the branches, favoring one spin state and resulting in the anomalous Josephson effect. We successfully demonstrated the excitation of the direct spin-flip transition using all-electrical control, which could enable the future implementation of charging energy protected Andreev spin qubits.
PHYSICAL REVIEW LETTERS
(2023)
Article
Materials Science, Multidisciplinary
H. Q. Nguyen, D. Sabonis, D. Razmadze, E. T. Mannila, V. F. Maisi, D. M. T. Zanten, E. C. T. O'Farrell, P. Krogstrup, F. Kuemmeth, J. P. Pekola, C. M. Marcus
Summary: We demonstrate the electrostatic control of quasiparticle poisoning in superconducting devices using single-charge tunneling across a fixed barrier onto a Coulomb island. High-bandwidth charge sensing is used to monitor the charge occupancy of the island, and electrostatic gates are shown to significantly affect the tunneling rates by two orders of magnitude. The gate dependence of the superconducting gap size and softness on the island is corroborated by separate density-of-states measurements.
Article
Physics, Applied
T. Stavenga, S. A. Khan, Y. Liu, P. Krogstrup, L. DiCarlo
Summary: Quantum hardware based on circuit quantum electrodynamics utilizes airbridges to suppress unwanted wave propagation modes and enable transmission lines to cross. Grayscale lithography is used to reduce the peak temperature of the airbridge fabrication process and increase the physical yield of transmon qubits with Josephson elements.
APPLIED PHYSICS LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Pablo San-Jose, Carlos Paya, C. M. Marcus, S. Vaitiekenas, Elsa Prada
Summary: Full-shell nanowires are hybrid nanostructures with a semiconducting core and a superconducting shell. We theoretically show that these nanowires can exhibit CdGM analogs, which are subgap states induced by the shell. The skewness of the CdGM analogs inside nonzero LP lobes can be used to extract microscopic information.
Article
Materials Science, Multidisciplinary
D. Razmadze, R. Seoane Souto, L. Galletti, A. Maiani, Y. Liu, P. Krogstrup, C. Schrade, A. Gyenis, C. M. Marcus, S. Vaitiekenas
Summary: We report supercurrent transport measurements in hybrid Josephson junctions consisting of semiconducting InAs nanowires with epitaxial ferromagnetic insulator EuS and superconducting Al coatings. The wires exhibit a hysteretic superconducting window near the coercivity, away from zero external magnetic field. Using a multi-interferometer setup, we measure the current-phase relation of multiple magnetic junctions and observe an abrupt switch between pi and 0 phases within the superconducting window. We attribute the 0-pi transition to the discrete flipping of EuS domains and provide a qualitative theory showing that a sizable exchange field can polarize the junction and lead to the supercurrent reversal. Both 0 and pi phases can be achieved at zero external field by demagnetizing the wire.
Article
Chemistry, Physical
Soumyadip Mondal, Rajesh B. Jethwa, Bhargavi Pant, Robert Hauschild, Stefan A. Freunberger
Summary: Singlet oxygen (1O2) formation is a key aspect of non-aqueous oxygen redox chemistry. We provided direct spectroscopic evidence for previously proposed pathways of 1O2 formation and identified a new pathway. Chemical trapping with 9,10-dimethylanthracene (DMA) is a reliable method to assess 1O2 formation.
FARADAY DISCUSSIONS
(2023)
Article
Materials Science, Multidisciplinary
O. Erlandsson, D. Sabonis, A. Kringhoj, T. W. Larsen, P. Krogstrup, K. D. Petersson, C. M. Marcus
Summary: The rate of charge-parity switching in a full-shell superconductor-semiconductor nanowire qubit is measured and found to decrease with increasing temperature or magnetic field, resulting in a decrease in the qubit lifetime.
