Article
Physics, Fluids & Plasmas
Anderson L. R. Barbosa, Jonas R. F. Lima, Luiz Felipe C. Pereira
Summary: We investigate the propagation of waves in one-dimensional systems with Levy-type disorder. We find that nonrelativistic and relativistic waves exhibit anomalous localization when the potential barriers' width, separation, or both follow Levy distributions. Furthermore, in the case where both parameters follow a Levy distribution, nonrelativistic and relativistic waves undergo a transition from anomalous to standard localization as the incidence energy increases.
Article
Multidisciplinary Sciences
R. Mendez-Camacho, E. Cruz-Hernandez
Summary: Vertically aligned arrays are commonly formed in the synthesis and processing of nanowires. Quantum electron tunneling can occur between these nanowires when they are close to each other, and the tunneling configuration can be adjusted by an external gate. This study investigates the electron interaction between closely spaced, parallel nanowires by considering the collective nature of electrons. At low densities, tunneling can occur between adjacent localized states in the nanowires.
SCIENTIFIC REPORTS
(2022)
Article
Chemistry, Multidisciplinary
Molly P. Andersen, Evgeny Mikheev, Ilan T. Rosen, Lixuan Tai, Peng Zhang, Kang L. Wang, Marc A. Kastner, David Goldhaber-Gordon
Summary: The quantum coherence-driven universal conductance fluctuations in the topological material MnBi2Te4 thin film were studied. It was found that the conductance magnetofingerprint depends on the direction of the magnetic field sweep, which may be due to the motion and nucleation of magnetic domain walls.
Article
Physics, Multidisciplinary
N. Arabchigavkani, R. Somphonsane, H. Ramamoorthy, G. He, J. Nathawat, S. Yin, B. Barut, K. He, M. D. Randle, R. Dixit, K. Sakanashi, N. Aoki, K. Zhang, L. Wang, W-N Mei, P. A. Dowben, J. Fransson, J. P. Bird
Summary: Mesoscopic conductance fluctuations are a common feature in small conductors, but this study reveals a breakdown of universality due to the interplay of local and remote phenomena in transport. The experiments demonstrate that remote factors can significantly impact conductivity in phase-coherent conductors, leading to giant conductance fluctuations exceeding theoretical predictions.
PHYSICAL REVIEW LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Run Xiao, Saurav Islam, Wilson Yanez, Yongxi Ou, Haiwen Liu, Xincheng Xie, Juan Chamorro, Tyrel M. McQueen, Nitin Samarth
Summary: Time-reversal invariance and inversion symmetry are responsible for the topological band structure in Dirac semimetals. Applying an external magnetic or electric field can break these symmetries and cause fundamental changes to the ground state Hamiltonian and a topological phase transition. We use universal conductance fluctuations in Cd3As2 to probe these changes. The magnitude of the fluctuations decreases with increasing magnetic field, consistent with the effect of broken time-reversal invariance. However, the magnitude increases monotonically when the chemical potential is gated away from the charge neutrality point, attributed to Fermi surface anisotropy rather than broken inversion symmetry. The agreement between experimental data and theory provides unequivocal evidence that universal conductance fluctuations are the dominant source of fluctuations and offers a general methodology for probing broken-symmetry effects in topological quantum materials.
Article
Physics, Applied
Po-Yu Chien, Chih-Yuan Wu, Ruey-Tay Wang, Shao-Pin Chiu, Stefan Kirchner, Sheng-Shiuan Yeh, Juhn-Jong Lin
Summary: We conducted measurements on 1/f noise of IrO2 nanowires from 1.7 to 350 K. The findings indicate an increase in noise magnitude at low temperatures, suggesting the presence of low-frequency resistance noise arising from universal conductance fluctuations. This noise is attributed to oxygen vacancies in the rutile structure of IrO2. Furthermore, the number density of these mobile defects can be determined by calculating the vT resistance rise caused by the two-channel Kondo effect in the Dirac nodal line metal IrO2.
APPLIED PHYSICS LETTERS
(2023)
Article
Nanoscience & Nanotechnology
Tae-Eon Park, Byoung-Chul Min, Jaejun Lee, Jeehoon Jeon, Ki-Young Lee, Heon-Jin Choi, Joonyeon Chang
Summary: Gallium nitride nanowires with triangular cross-section show universal conductance fluctuations due to quantum interference of electron wave functions, with phase coherent transport dominating over normal transport. The phase-coherence length extracted from UCF is large at low temperatures and decreases as temperature increases.
Article
Physics, Fluids & Plasmas
N. L. Pessoa, A. L. R. Barbosa, G. L. Vasconcelos, A. M. S. Macedo
Summary: It is found that multifractality is present in the magnetoconductance data of two different types of mesoscopic systems under the influence of a magnetic field. The phenomenon becomes more pronounced when the number of scattering channels is small. The distributions of conductance increments fitted well with q Gaussians, with the parameter q serving as a useful quantitative measure of multifractality in magnetoconductance fluctuations.
Article
Physics, Multidisciplinary
A. A. Zhukov
Summary: This article presents measurements of magnetotransport in high quality InN nanowires using a conductive atomic-force microscope tip at a temperature of 4.2 K. The study demonstrates the influence of the nearby atomic-force microscope tip on the nanowires at certain ranges of back gate voltages, with a decrease in influence observed in an external magnetic field of B >= 150 mT. The observed behavior is explained by the presence of branched current beneath the surface of the InN nanowire, similar to that observed in heterostructures and graphene samples with point contacts.
Article
Engineering, Electrical & Electronic
Erik Zimmermann, Jonas Koelzer, Michael Schleenvoigt, Daniel Rosenbach, Gregor Mussler, Peter Schueffelgen, Tristan Heider, Lukasz Plucinski, Juergen Schubert, Hans Lueth, Detlev Gruetzmacher, Thomas Schaepers
Summary: We conducted low-temperature magnetotransport measurements on the promising quaternary Bi1.5Sb0.5Te1.8Se1.2 topological insulator material. The measurements on a nano-Hall bar grown by selective-area molecular beam epitaxy revealed significant universal conductance fluctuations. It was found that these fluctuations originated from phase-coherent loops within the topologically protected surface states. Furthermore, the decrease in fluctuation amplitude with increasing temperatures suggests a quasi one-dimensional transport regime.
SEMICONDUCTOR SCIENCE AND TECHNOLOGY
(2023)
Article
Materials Science, Multidisciplinary
Xiaotian Yang, Weiqing Zhou, Qi Yao, Pengfei Lv, Yunhua Wang, Shengjun Yuan
Summary: This study models the SC fractals formed by hydrogen and fluorine functionalized patterns on graphene surfaces, and investigates their electronic properties and quantum transport features. It is found that the energy states in H-SC and F-SC are localized in different graphene regions, and the conductance fluctuations in these structures follow the Hausdorff dimension.
Article
Physics, Multidisciplinary
Vladislav D. Kurilovich, Leonid I. Glazman
Summary: This article develops a theory of the nonlocal transport of two counterpropagating nu = 1 quantum Hall edges coupled via a narrow disordered superconductor. Contrary to predictions, the edge states proximitized in this way do not turn into a topological superconductor, but are tuned to the critical point between trivial and topological phases.
Article
Physics, Multidisciplinary
Rubah Kausar, Chao Zheng, Xin Wan
Summary: Recent experiments have shown the realization of the three-dimensional quantum Hall effect in highly anisotropic crystalline materials, exhibiting a one-dimensional metal-insulator crossover. Researchers found a wide crossover of the level-spacing distribution through a semi-Poisson distribution, and a nonmonotonic evolution of the level statistics due to the disorder-induced mixture of surface and bulk states.
CHINESE PHYSICS LETTERS
(2021)
Article
Multidisciplinary Sciences
Lijun Zhu, Xiaoqiang Liu, Lin Li, Xinyi Wan, Ran Tao, Zhongniu Xie, Ji Feng, Changgan Zeng
Summary: By conducting magneto-drag experiments on graphene-based double-layer systems, Zhu et al. identify a new type of inter-layer quantum interference, which arises from interference between carrier diffusion paths across the constituent layers. This finding provides an ideal platform to study the interplay between quantum interference and many-body interactions.
NATURE COMMUNICATIONS
(2023)
Article
Multidisciplinary Sciences
Damianos Chatzopoulos, Doohee Cho, Koen M. Bastiaans, Gorm O. Steffensen, Damian Bouwmeester, Alireza Akbari, Genda Gu, Jens Paaske, Brian M. Andersen, Milan P. Allan
Summary: By using scanning tunneling microscopy (STM), dispersive in-gap states in the iron-based superconductor FeTe0.55Se0.45 were found and characterized, along with the discovery of YSR-type impurity states. The use of a superconducting STM tip allowed for enhanced energy resolution and the tuning of impurity states through the Fermi level. The experimental data was well explained by modeling the tip-gating scenario within the single-impurity Anderson model.
NATURE COMMUNICATIONS
(2021)
Article
Chemistry, Physical
Ionel Stavarache, Ovidiu Cojocaru, Valentin Adrian Maraloiu, Valentin Serban Teodorescu, Toma Stoica, Magdalena Lidia Ciurea
Summary: This study investigated Al2O3/Ge/Al2O3 trilayer memory structures deposited on p-Si substrates, revealing different effects of rapid thermal annealing (RTA) at various temperatures on the structure, morphology, and memory properties. The results showed changes in Ge diffusion, formation of Ge nanocrystals and mixed oxide nanoparticles at different annealing temperatures, leading to variations in the memory window size and charge loss behavior over time.
APPLIED SURFACE SCIENCE
(2021)
Article
Multidisciplinary Sciences
Jinzhong Zhang, Pok-Lam Tse, Abdur-Rehman Jalil, Jonas Koelzer, Daniel Rosenbach, Martina Luysberg, Gregory Panaitov, Hans Lueth, Zhigao Hu, Detlev Gruetzmacher, Jia Grace Lu, Thomas Schaepers
Summary: Despite the limited knowledge on the low-temperature transport properties of GeTe, this study reveals phase-coherent phenomena in GeTe nanowires. The magnetic flux-periodic oscillations observed in the study are attributed to the formation of a tubular hole accumulation layer.
NATURE COMMUNICATIONS
(2021)
Article
Multidisciplinary Sciences
Ovidiu Cojocaru, Ana-Maria Lepadatu, George Alexandru Nemnes, Toma Stoica, Magdalena Lidia Ciurea
Summary: A detailed study on the bandgap dependence of spherical Ge-rich GexSi1-x nanocrystals was conducted using atomistic density functional theory calculations. The results show a composition invariance of the bandgap diameter dependence, with the bandgap of NCs being well described by a power function for a certain diameter range. H-passivation of the NC surface helps accurately determine the NC bandgap by excluding surface states near the band edges.
SCIENTIFIC REPORTS
(2021)
Article
Multidisciplinary Sciences
Daniel Rosenbach, Tobias W. Schmitt, Peter Schueffelgen, Martin P. Stehno, Chuan Li, Michael Schleenvoigt, Abdur R. Jalil, Gregor Mussler, Elmar Neumann, Stefan Trellenkamp, Alexander A. Golubov, Alexander Brinkman, Detlev Gruetzmacher, Thomas Schaepers
Summary: The article discusses the discovery of a 4 pi periodic current phase relation in Josephson junctions with topological weak links and the attenuation and quantization phenomena observed in certain structures.
Article
Materials Science, Multidisciplinary
Pujitha Perla, Anton Faustmann, Sebastian Koelling, Patrick Zellekens, Russell Deacon, H. Aruni Fonseka, Jonas Koelzer, Yuki Sato, Ana M. Sanchez, Oussama Moutanabbir, Koji Ishibashi, Detlev Gruetzmacher, Mihail Ion Lepsa, Thomas Schaepers
Summary: Semiconductor nanowires play a versatile role as components in superconducting hybrid devices for Majorana physics and quantum computing. The transport properties of nanowires can be controlled by field effect or doping. This study focused on investigating the conductivity of InAs nanowires that had been modified by n-type doping, and found that the transport properties could be tuned by adjusting the dopant concentration.
PHYSICAL REVIEW MATERIALS
(2022)
Article
Physics, Multidisciplinary
Patrick Zellekens, Russell Deacon, Pujitha Perla, Detlev Gruetzmacher, Mihail Ion Lepsa, Thomas Schaepers, Koji Ishibashi
Summary: In this study, low-loss superconducting microwave circuits were fabricated using a flip-chip method, and the intrinsic excitation spectrum of nanowire Josephson junctions was studied spectroscopically using this platform. The experimental results showed clear transitions between single quasiparticles and quasiparticle pairs in specific conditions.
COMMUNICATIONS PHYSICS
(2022)
Article
Engineering, Electrical & Electronic
Erik Zimmermann, Jonas Koelzer, Michael Schleenvoigt, Daniel Rosenbach, Gregor Mussler, Peter Schueffelgen, Tristan Heider, Lukasz Plucinski, Juergen Schubert, Hans Lueth, Detlev Gruetzmacher, Thomas Schaepers
Summary: We conducted low-temperature magnetotransport measurements on the promising quaternary Bi1.5Sb0.5Te1.8Se1.2 topological insulator material. The measurements on a nano-Hall bar grown by selective-area molecular beam epitaxy revealed significant universal conductance fluctuations. It was found that these fluctuations originated from phase-coherent loops within the topologically protected surface states. Furthermore, the decrease in fluctuation amplitude with increasing temperatures suggests a quasi one-dimensional transport regime.
SEMICONDUCTOR SCIENCE AND TECHNOLOGY
(2023)
Article
Physics, Applied
Tobias W. Schmitt, Benedikt Frohn, Wilhelm Wittl, Abdur R. Jalil, Michael Schleenvoigt, Erik Zimmermann, Anne Schmidt, Thomas Schaepers, Juan Carlos Cuevas, Alexander Brinkman, Detlev Gruetzmacher, Peter Schueffelgen
Summary: In this study, the temperature-dependent behavior of a Bi2Te3-based Josephson junction (JJ) with transparent interfaces is investigated, providing insights into the contributions of bulk and surface states in topological insulator JJs. Differential conductance spectra of multiple Andreev reflections (MARs) are measured in electrical transport experiments, showing a qualitative temperature-dependent change from peak features to dip features. The observation of both types of MAR patterns in a single JJ suggests the presence of diffusive bulk and ballistic surface states, and their connection to the temperature dependence of the critical current. This work advances the understanding of induced superconductivity in topological insulators and offers new avenues for studying induced superconductivity in the topological surface states of these materials.
SUPERCONDUCTOR SCIENCE & TECHNOLOGY
(2023)
Article
Chemistry, Multidisciplinary
Jonas Koelzer, Abdur Rehman Jalil, Daniel Rosenbach, Lisa Arndt, Gregor Mussler, Peter Schueffelgen, Detlev Gruetzmacher, Hans Lueth, Thomas Schaepers
Summary: In this paper, the transport properties of an in situ prepared three-terminal Josephson junction based on the topological insulator Bi4Te3 and the superconductor Nb are studied. The differential resistance maps reveal extended areas of Josephson supercurrent, including coupling effects between adjacent superconducting electrodes. The experimental results are interpreted using a numerical simulation based on a resistively and capacitively shunted Josephson junction model.
Article
Physics, Multidisciplinary
Takahito Saito, Toshimichi Nishimura, Ju-Young Yoon, Jonas Koelzer, Daisuke Iizasa, Michael Kammermeier, Thomas Schaepers, Junsaku Nitta, Makoto Kohda
Summary: In this study, the lifetime of helical and homogeneous spin modes near the persistent spin helix (PSH) state is investigated using electrical means. The experiments reveal that the relaxation rates of these spin modes are modulated by the ratio of Rashba and Dresselhaus spin-orbit coefficients. This finding opens up new avenues for exploring electron spin textures in various materials, from semiconductors to metals.
PHYSICAL REVIEW RESEARCH
(2022)
Article
Physics, Multidisciplinary
Daniel Rosenbach, Kristof Moors, Abdur R. Jalil, Jonas Koelzer, Erik Zimmermann, Jurgen Schubert, Soraya Karimzadah, Gregor Mussler, Peter Schueffelgen, Detlev Gruetzmacher, Hans Lueth, Thomas Schaepers
Summary: Three-dimensional topological insulators host helical Dirac surface states. In quasi-one-dimensional TI nanoribbon structures, the wave function of surface charges extends phase-coherently along the perimeter of the nanoribbon, resulting in a quantization of transverse surface modes. Researchers have found that the transverse surface states along the perimeter of the nanoribbon can be controlled by changing the top gate potential.
SCIPOST PHYSICS CORE
(2022)
Article
Materials Science, Multidisciplinary
Jonas Koelzer, Kristof Moors, Abdur Rehman Jalil, Erik Zimmermann, Daniel Rosenbach, Lidia Kibkalo, Peter Schueffelgen, Gregor Mussler, Detlev Gruetzmacher, Thomas L. Schmidt, Hans Lueth, Thomas Schaepers
Summary: This study investigates the magnetotransport properties of three-terminal junctions in three-dimensional topological insulator nanoribbons, revealing that an in-plane magnetic field can affect the current flow direction, achieving a steering effect on the surface state current. This steering effect, originating from the orbital effect, breaks the left-right symmetry of the junction by trapping phase-coherent surface states in different branches on opposite sides of the nanoribbon.
COMMUNICATIONS MATERIALS
(2021)
Article
Chemistry, Multidisciplinary
Pujitha Perla, H. Aruni Fonseka, Patrick Zellekens, Russell Deacon, Yisong Han, Jonas Koelzer, Timm Moerstedt, Benjamin Bennemann, Abbas Espiari, Koji Ishibashi, Detlev Gruetzmacher, Ana M. Sanchez, Mihail Ion Lepsa, Thomas Schaepers
Summary: Josephson junctions based on InAs semiconducting nanowires and Nb superconducting electrodes were fabricated in situ using a special shadow evaporation scheme. The junctions exhibit a clean InAs/Nb interface and a high junction transparency, with a clear Josephson supercurrent that can be controlled by a bottom gate. This in situ prepared Nb/InAs nanowire contacts show potential for use in superconducting quantum circuits requiring large magnetic fields.
NANOSCALE ADVANCES
(2021)
Correction
Materials Science, Multidisciplinary
Kristof Moors, Peter Schuffelgen, Daniel Rosenbach, Tobias Schmitt, Thomas Schapers, Thomas L. Schmidt
Proceedings Paper
Engineering, Electrical & Electronic
A. M. Lepadatu, C. Palade, A. Slav, I Dascalescu, O. Cojocaru, S. Iftimie, V. S. Teodorescu, T. Stoica, M. L. Ciurea
CAS 2020 PROCEEDINGS: 2020 INTERNATIONAL SEMICONDUCTOR CONFERENCE
(2020)
