Article
Nanoscience & Nanotechnology
Joydip Sarkar, Kishor Salunkhe, Supriya Mandal, Subhamoy Ghatak, Alisha H. Marchawala, Ipsita Das, Kenji Watanabe, Takashi Taniguchi, R. Vijay, Mandar M. Deshmukh
Summary: Josephson junctions (JJs) and their tunable properties are crucial for superconducting qubits and amplifiers. This study demonstrates a quantum-noise-limited Josephson parametric amplifier (JPA) using a graphene Josephson junction (JJ) with linear resonance gate tunability. The gate-tunable JPA exhibits high amplification performance and operates in the quantum-limited noise regime, making it an attractive option for sensitive signal processing.
NATURE NANOTECHNOLOGY
(2022)
Article
Chemistry, Physical
Wei Miao, Feiming Li, Qianghui Luo, Qingcheng Wang, Jiaqiang Zhong, Zheng Wang, Kangmin Zhou, Yuan Ren, Wen Zhang, Jing Li, Shengcai Shi, Cui Yu, Zezhao He, Qingbin Liu, Zhihong Feng
Summary: In this study, a lens-antenna coupled THz detector based on graphene was demonstrated, showing low electrical noise and good optical performance.
Article
Chemistry, Multidisciplinary
Jincan Zhang, Kaicheng Jia, Yongfeng Huang, Xiaoting Liu, Qiuhao Xu, Wendong Wang, Rui Zhang, Bingyao Liu, Liming Zheng, Heng Chen, Peng Gao, Sheng Meng, Li Lin, Hailin Peng, Zhongfan Liu
Summary: The study found that pristine graphene exhibits high hydrophilicity with an average water contact angle of approximately 30 degrees, due to charge transfer between graphene and water molecules. This work provides insight into water-graphene interaction and introduces a new approach for measuring surface properties of 2D materials.
ADVANCED MATERIALS
(2022)
Article
Multidisciplinary Sciences
Ko-Fan Huang, Yuval Ronen, Regis Melin, Denis Feinberg, Kenji Watanabe, Takashi Taniguchi, Philip Kim
Summary: In this study, the authors measured the interference effects of Cooper Quartets in a multi-terminal graphene Josephson junction and provided evidence for interference between different quartet processes. The experimental results showed periodic variations in the quartet differential conductance associated with charge and the behavior of the critical current can be modeled by transitions between Floquet-ABSs. This observation extends our understanding of multi-terminal Josephson junctions and paves the way for the future design of topologically unique ABS spectra.
NATURE COMMUNICATIONS
(2022)
Article
Physics, Applied
Zhujun Huang, Neda Lotfizadeh, Bassel H. Elfeky, Kim Kisslinger, Edoardo Cuniberto, Peng Yu, Mehdi Hatefipour, Takashi Taniguchi, Kenji Watanabe, Javad Shabani, Davood Shahrjerdi
Summary: Transparent contact interfaces are crucial for superconducting quantum applications in superconductor-graphene hybrid systems. By optimizing the edge contact fabrication process, we have achieved improved transparency in our superconductor-graphene junctions.
APPLIED PHYSICS LETTERS
(2022)
Article
Physics, Applied
N. G. Pugach, D. M. Heim, D. Seleznev, A. Chernov, D. Menzel
Summary: We propose a superconducting spin valve based on a Josephson junction with B20-family magnetic metal as a barrier material. By reorienting the magnetization of the spiral magnet, the states of this device can be switched, which strongly influences the critical Josephson current. Compared to previous superconducting spin valves, our device is easier to fabricate and control, has a stable ground state, and is compatible with low-T Josephson electronics.
SUPERCONDUCTOR SCIENCE & TECHNOLOGY
(2022)
Article
Materials Science, Multidisciplinary
Eduard Zsurka, Noel Plaszko, Peter Rakyta, Andor Kormanyos
Summary: We propose a device composed of two vertically stacked monolayer graphene Josephson junctions for Cooper pair splitting. The hybridization of Andreev bound states in the two Josephson junctions facilitates non-local transport in this normal-superconductor hybrid structure, as studied through the calculation of non-local differential conductance. Our setup offers the advantage of not requiring precise control over junction length, doping, or superconducting phase difference, making it potentially easier for experimental realization.
Article
Chemistry, Physical
Han Zhou, Xiuli Hu, Wei-Hai Fang, Neil Qiang Su
Summary: This research comprehensively studies the spin couplings between transition metal atoms doped on graphene and reveals their potential application in spintronic device design. It also verifies that the spin-coupling effect can exhibit a certain distance dependence and space propagation.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
Eri Widianto, Natalita Maulani Shobih, Natalita Maulani Nursam, Muhammad Yusrul Hanna, Kuwat Triyana, Andrivo Rusydi, Iman Santoso
Summary: We investigate the optical properties of methylammonium lead iodide (MAPbI3) combined with graphene oxide (GO) and reveal unusual optical changes and spectral weight transfer using spectroscopic ellipsometry. Our analysis shows that the electronic correlation effect induced by GO leads to tunable optical properties of MAPbI3. The increase in absorption in the MAPbI3 layer indicates a decrease in the number of holes, suggesting the hole transport properties of GO. This study provides critical information for the future development of high-performance PSCs and reconciles previous experimental studies on the positive impact of GO on charge extraction.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Physics, Applied
Takashi Sakamori, Satoshi Kashiwaya, Rikizo Yano, Yukio Tanaka, Takafumi Hatano, Keiji Yada
Summary: This paper investigates the origins of the suppression of critical current at grain boundaries in high-critical-temperature superconductors. The study reveals that an internal phase change can affect the threshold of the critical current, and a unique phase interference effect is observed in a lattice model. This model provides insights into the complicated transport mechanism at grain boundaries.
SUPERCONDUCTOR SCIENCE & TECHNOLOGY
(2023)
Article
Physics, Multidisciplinary
Shahrukh Salim, Rahul Marathe, Sankalpa Ghosh
Summary: In this study, we compare the theory with experimental results on charge transport through Josephson junctions made of graphene. A transfer matrix approach is used to analytically derive the spectrum of Andreev bound states (ABS) in a superconductor-graphene-superconductor junction, focusing on monolayer graphene. The theoretical results successfully explain both the retro Andreev reflection (RAR) and specular Andreev reflection (SAR) phenomena within the relevant parameter range. By evaluating the current and conductance using the ABS spectrum and experimental system parameters, we find good agreement with experimental results, with the calculated values showing scaling behavior with junction length and significantly lower values when RAR is dominant.
Article
Optics
Liangchen Hu, Yibo Dong, Jun Deng, Yiyang Xie, Xiaochen Ma, Fengsong Qian, Qiuhua Wang, Pan Fu, Chen Xu
Summary: The unique design of the graphene-InGaAs photodetector prolongs the lifetime of photogenerated carriers, improves response performance, and achieves high responsivity and photoconductive gain. Additionally, a saturation phenomenon of light response was observed and explained by the capacitance theory of the built-in electric field, with theoretical calculations matching measurement results.
Article
Physics, Multidisciplinary
J. Tang, M. T. Wei, A. Sharma, E. G. Arnault, A. Seredinski, Y. Mehta, K. Watanabe, T. Taniguchi, F. Amet, I Borzenets
Summary: The study reveals that Josephson junctions made of encapsulated graphene boron nitride heterostructures exhibit non-hysteretic behavior in the zero-bias regime and follow scaling laws dictated by the phase diffusion mechanism. By varying the carrier concentration of graphene, it is confirmed that the observed phase diffusion mechanism resembles the characteristics of overdamped Josephson junctions, which stands in contrast to the majority of graphene-based junctions that are underdamped.
PHYSICAL REVIEW RESEARCH
(2022)
Article
Chemistry, Multidisciplinary
Jesse Balgley, Jackson Butler, Sananda Biswas, Zhehao Ge, Samuel Lagasse, Takashi Taniguchi, Kenji Watanabe, Matthew Cothrine, David G. Mandrus, Jairo Velasco, Roser Valenti, Erik A. Henriksen
Summary: In this study, we demonstrate ultrasharp lateral p-n junctions in graphene using electronic transport, scanning tunneling microscopy, and first-principles calculations. These junctions are formed at the boundary between differently doped regions of a graphene sheet, with one side being intrinsic and the other side being charge-doped by proximity to an alpha-RuCl3 flake. Our results show potential variations on a sub 10 nm length scale in heterostructures of graphene, hexagonal boron nitride, and alpha-RuCl3. First-principles calculations reveal a sharp decay of charge-doping from the edge of the alpha-RuCl3 flake within just a few nanometers.
Article
Engineering, Electrical & Electronic
Haruhisa Kitano
Summary: Intrinsic Josephson junctions (IJJs) in high-Tc cuprate superconductors have fascinating properties that surpass conventional Josephson junctions from low-Tc superconductors. These properties include very thin superconducting layers, strong atomic-scale connections between neighboring junctions, and clean interfaces between superconducting and insulating layers in single crystals with few disorders. The unique properties of IJJs can expand the application of superconducting qubits, allowing for higher qubit-operation temperatures and novel applications involving macroscopic quantum states with internal degree of freedom. This paper provides a comprehensive review of phase dynamics in current-biased IJJs and discusses the challenges of utilizing IJJs in superconducting qubits.
IEICE TRANSACTIONS ON ELECTRONICS
(2023)
