Maciej.bazarnik

Engineering the spin couplings in atomically crafted spin chains on an elemental superconductor

Engineering the spin couplings in atomically crafted spin chains on an elemental superconductor, Published online: 14 August 2018; doi:10.1038/s41467-018-05701-8

Iron-based trinuclear metal-organic nanostructures on a surface with local charge accumulation

Iron-based trinuclear metal-organic nanostructures on a surface with local charge accumulation, Published online: 10 August 2018; doi:10.1038/s41467-018-05543-4

Inducing Kondo screening of vacancy magnetic moments in graphene with gating and local curvature

Inducing Kondo screening of vacancy magnetic moments in graphene with gating and local curvature, Published online: 14 June 2018; doi:10.1038/s41467-018-04812-6

Author(s): Y. Pavlyukh, E. Rentschler, H. J. Elmers, W. Hübner, and G. Lefkidis

Electronic and magnetic properties of molecular nanomagnets are determined by competing energy scales due to the crystal field splitting, the exchange interactions between transition metal atoms, and relativistic effects. We present a comprehensive theory embracing all these phenomena based on first...

[Phys. Rev. B 97, 214408] Published Fri Jun 08, 2018

Conventional scanning tunneling microscopy (STM) is limited to a bandwidth of circa 1kHz around DC. Here, we develop, build and test a novel amplifier circuit capable of measuring the tunneling current in the MHz regime while simultaneously performing conventional STM measurements. This is achieved with an amplifier circuit including a LC tank with a quality factor exceeding 600 and a home-built, low-noise high electron mobility transistor (HEMT). The amplifier circuit functions while simultaneously scanning with atomic resolution in the tunneling regime, i.e. at junction resistances in the range of giga-ohms, and down towards point contact spectroscopy. To enable high signal-to-noise and meet all technical requirements for the inclusion in a commercial low temperature, ultra-high vacuum STM, we use superconducting cross-wound inductors and choose materials and circuit elements with low heat load. We demonstrate the high performance of the amplifier by spatially mapping the Poissonian noise of tunneling electrons on an atomically clean Au(111) surface. We also show differential conductance spectroscopy measurements at 3MHz, demonstrating superior performance over conventional spectroscopy techniques. Further, our technology could be used to perform impedance matched spin resonance and distinguish Majorana modes from more conventional edge states.

Author(s): Shuang Wu, Bing Liu, Cheng Shen, Si Li, Xiaochun Huang, Xiaobo Lu, Peng Chen, Guole Wang, Duoming Wang, Mengzhou Liao, Jing Zhang, Tingting Zhang, Shuopei Wang, Wei Yang, Rong Yang, Dongxia Shi, Kenji Watanabe, Takashi Taniguchi, Yugui Yao, Weihua Wang, and Guangyu Zhang

The determination of the electronic structure by edge geometry is unique to graphene. In theory, an evanescent nonchiral edge state is predicted at the zigzag edges of graphene. Up to now, the approach used to study zigzag-edged graphene has mostly been limited to scanning tunneling microscopy. The ...

[Phys. Rev. Lett. 120, 216601] Published Tue May 22, 2018

Author(s): J. Brand, S. Gozdzik, N. Néel, J. L. Lado, J. Fernández-Rossier, and J. Kröger

The interplay of magnetism and superconductivity gives rise to the emergence of various interesting phenomena in condensed matter physics, such as the Yu-Shiba-Rusinov in-gap modes created by local magnetic moments in superconducting hosts. Using normal-metal and superconducting tips the authors have formed contacts to an individual magnetic molecule adsorbed on a conventional superconductor. Spectroscopy of the differential conductance with tunable junction transparency has unveiled the crossover from quasiparticle tunneling, which probes the Bardeen-Cooper-Schrieffer energy gap as well as the Yu-Shiba-Rusinov levels, to the contact range where multiple Andreev reflection takes over.

[Phys. Rev. B 97, 195429] Published Thu May 17, 2018