Article
Chemistry, Multidisciplinary
Gunta Kunakova, Edijs Kauranens, Kiryl Niherysh, Mikhael Bechelany, Krisjanis Smits, Gatis Mozolevskis, Thilo Bauch, Floriana Lombardi, Donats Erts
Summary: Researchers investigated all-around ZnO-encapsulated Bi2Se3 nanoribbons and found them to have improved charge transport characteristics compared to nanoribbons grown on SiO2 substrates, due to reduced carrier densities at the nanoribbon/substrate interface.
Article
Physics, Multidisciplinary
Tae Gwan Park, Jae Ho Jeon, Seung-Hyun Chun, Sunghun Lee, Fabian Rotermund
Summary: This study investigates the interface effects between VSe2 and topological insulator Bi2Se3 using ultrafast time-resolved spectroscopy. The results show that VSe2 as an electrode does not alter the surface state of Bi2Se3 and enables efficient electron transfer and current flow.
COMMUNICATIONS PHYSICS
(2022)
Article
Nanoscience & Nanotechnology
Faizan Ahmad, Rachana Kumar, Sunil Singh Kushvaha, Mahesh Kumar, Pramod Kumar
Summary: This study analyzed the n-GaN/p-Bi2Se3 topological heterojunction using Raman spectroscopy and ultrafast transient absorption spectroscopy, exploring the surface states, energy levels, charge transfer, and carrier relaxation processes. Electrical measurements were also conducted to investigate the influence of interface states on the electrical and optical performance.
NPJ 2D MATERIALS AND APPLICATIONS
(2022)
Article
Physics, Applied
Shailja Sharma, Shiv Kumar, Amit Kumar, Kenya Shimada, C. S. Yadav
Summary: This study presents the structural, magnetotransport, and angle-resolved photoemission spectroscopy (ARPES) of Ag-doped Bi2Se3 single crystals. The results show that Ag-doping leads to metallic behavior in the resistivity, magnetoresistance satisfying Kohler's rule, and the dominance of electrons as charge carriers. The ARPES spectra confirm the shift of the Dirac point of the topological surface states towards higher binding energy for Ag-doped samples.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Chemistry, Multidisciplinary
Christian Nweze, Tomke E. Glier, Mika Rerrer, Sarah Scheitz, Yalan Huang, Robert Zierold, Robert Blick, Wolfgang J. Parak, Nils Huse, Michael Ruebhausen
Summary: In this study, the plasmonic gold nanoparticles injecting hot carriers into the topological insulator interface of Bi2Se3 nanoribbons were investigated using resonant Raman spectroscopy. The impact of individual gold particles with different sizes on the topological surface states and the phonon modes were resolved. The findings suggest the possibility of locally controlling the electronic properties of the topological insulator by metal nanoparticles through hot carrier injection.
Article
Physics, Applied
Gunta Kunakova, Thilo Bauch, Xavier Palermo, Matteo Salvato, Jana Andzane, Donats Erts, Floriana Lombardi
Summary: The study demonstrates that using SrTiO3 substrate in topological insulator nanoribbons enables tunability of Fermi energy and an ambipolar field effect, while maintaining high mobility of Dirac electrons for transportation, providing an ideal platform to take advantage of the properties of topological surface states.
PHYSICAL REVIEW APPLIED
(2021)
Article
Physics, Applied
Yanan Liu, Zhongyao Li
Summary: The coupling of topological interface states in Bi2Se3/Bi2Se3 and TlSe/TlSe junctions leads to an energy gap at the Dirac point, which exponentially decays with increasing interface spacing. The law of exponential decay can help identify the formation of interface states and suggests that the coupling is caused by quantum tunneling. Intercalating hexagonal BN can greatly enhance the interfacial coupling, while bilayer BN or single atomic Au layer intercalation can further enhance this coupling effect.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2021)
Article
Chemistry, Analytical
Yujiu Jiang, Peng Zhu, Jinge Zhao, Shanshan Li, Yetong Wu, Xiaolu Xiong, Xu Zhang, Yuxiang Liu, Jiangyue Bai, Zihang Wang, Shiqi Xu, Minxuan Wang, Tinglu Song, Zhiwei Wang, Weizhi Wang, Junfeng Han
Summary: In this work, a facile and label-free electrochemical biosensor based on intrinsic topological insulator (TI) Bi2Se3 and peptide was designed for the detection of immune checkpoint molecules. The biosensor showed stable and sensitive electron transport due to the robust surface states of Bi2Se3 with low electronic noise. The peptide served as a suitable recognition unit for immune checkpoint molecules, as it could be easily synthesized and chemically modified, and had good biocompatibility and bioavailability. The designed peptide/Bi2Se3 biosensor demonstrated a linear detection range from 3.6 x 10-10 mg mL-1 to 3.6 x 10-5 mg mL-1 and a detection limit of 1.07 x 10-11 mg mL-1. It also exhibited good selectivity and stability.
ANALYTICA CHIMICA ACTA
(2023)
Article
Physics, Applied
Muhammad Nadeem, Chao Zhang, Dimitrie Culcer, Alex R. Hamilton, Michael S. Fuhrer, Xiaolin Wang
Summary: By employing a gate-induced topological quantum phase transition, edge state transport in a topological insulator material can be controlled. This study suggests that zigzag-Xene nanoribbons are promising materials for topological electronics, displaying unique physical characteristics related to intrinsic band topology and finite-size effects on gate-induced topological switching.
APPLIED PHYSICS REVIEWS
(2022)
Article
Materials Science, Multidisciplinary
Na Li, Yun-bin Sun, Rui Sun, Xu Yang, Wei Zhang, Zong-kai Xie, Jia-nan Liu, Yan Li, Yang Li, Zi-zhao Gong, Xiang-qun Zhang, Wei He, Zhao-hua Cheng
Summary: Topological insulators with distinct topological surface states have been widely investigated for spintronics and quantum information devices. This study reveals that the topological surface states can significantly accelerate ultrafast demagnetization and enhance the damping factor of heterostructures. These findings have implications for future topological spintronic devices or quantum information processing.
Article
Engineering, Electrical & Electronic
Yogesh Kumar, Prince Sharma, V. P. S. Awana
Summary: In this study, bismuth selenide thin films of varying thicknesses were deposited on a SiO2 substrate. The films were characterized and their transport properties were investigated, revealing the thickness dependence of weak anti-localization effect in Bi2Se3/SiO2 thin films.
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
(2022)
Article
Chemistry, Physical
Dan Wang, Cui-E Hu, Li-Gang Liu, Min Zhang, Xiang-Rong Chen
Summary: In this study, an effective method to introduce magnetism into topological insulators was obtained, and single crystal C-Bi2Se3 was successfully fabricated. The structural, electrical and magnetic properties of doped non-magnetic element X (B, C, and N) in Bi, Se1, Se2, and VDW gap sites of Bi2Se3 were investigated. It was found that C doping in Bi2Se3 resulted in the formation of impurity bands inside the bulk inverted energy gap near the Fermi level. Theoretical calculations and experiments confirmed that carbon-doped Bi2Se3 is ferromagnetic, which provides a plan for manipulating topological properties and exploring spintronic applications.
Article
Nanoscience & Nanotechnology
Wen Wang, Haocheng Lei, Ashu Wang
Summary: In this study, the friction behavior of Bi2Se3 was investigated using conductive friction force microscopy under ultra-high vacuum conditions. The experimental results revealed a non-monotonic enhancement of friction, with the emergence of two friction peaks. Further investigations demonstrated that this anomalous friction behavior originated from the formation and rupture of multiple thermally activated sub-contacts.
Article
Quantum Science & Technology
Jonghoon Kim, Kwangsik Jeong, Hanbum Park, Seokbo Hong, Dajung Kim, Gihwan Nam, Seungwon Rho, Hee Jun Shin, Chul Kang, Mann-Ho Cho
Summary: In this work, the suppression of surface properties in Bi2Se3 of various thicknesses grown on antiferromagnetic NiO, which has a strong exchange interaction is investigated. The study found that under perpendicular magnetic fields, a drastic decrease in mobility mu and in the number of phase coherent channels alpha in 5 QL Bi2Se3 on NiO are observed. Additionally, the THz transmission study shows that an increase in the surface penetration depth xi can accelerate the hybridization of surface states, which is also verified using the optical pump THz probe. This rapid collapse of surface states indicates the unique role of antiferromagnetic materials in band overlap, suggesting that the topological surface nature can be modulated by forming an antiferromagnet-topological insulator heterostructure.
ADVANCED QUANTUM TECHNOLOGIES
(2023)
Article
Chemistry, Physical
Mao Ye, Kenta Kuroda, Mikhail M. Otrokov, Anastasia G. Ryabishchenkova, Qi Jiang, Arthur Ernst, Evgueni Chulkov, Masashi Nakatake, Masashi Arita, Taichi Okuda, Tomohiro Matsushita, Laszlo Toth, Hiroshi Daimon, Kenya Shimada, Yoshifumi Ueda, Akio Kimura
Summary: The study reveals that deposited Ag atoms on the topological insulator Bi2Se3 surface are stabilized beneath the surface instead of being adsorbed on the topmost surface. The presence of Ag atoms does not disturb the topological surface states. Through angle-resolved photoemission spectroscopy and first-principles calculations, the distribution and most favorable locations of Ag atoms beneath the surface are identified.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Multidisciplinary Sciences
F. Borjans, X. G. Croot, X. Mi, M. J. Gullans, J. R. Petta
Review
Physics, Multidisciplinary
A. A. Clerk, K. W. Lehnert, P. Bertet, J. R. Petta, Y. Nakamura
Article
Physics, Applied
F. Borjans, X. Croot, S. Putz, X. Mi, S. M. Quinn, A. Pan, J. Kerckhoff, E. J. Pritchett, C. A. Jackson, L. F. Edge, R. S. Ross, T. D. Ladd, M. G. Borselli, M. F. Gyure, J. R. Petta
APPLIED PHYSICS LETTERS
(2020)
Article
Physics, Applied
F. Borjans, X. Mi, J. R. Petta
Summary: The study demonstrates high-fidelity spin readout using a charge sensor within a triple quantum dot, achieving near-digital sensor response and over 450 power signal-to-noise ratio at an integration time of 1 μs. The approach enables measurement of spin relaxation time and achieves greater than 99% average single-shot spin readout fidelity for singlet-triplet qubit, combining minimal device overhead with flexible qubit operation in semiconductor quantum devices.
PHYSICAL REVIEW APPLIED
(2021)
Article
Nanoscience & Nanotechnology
Seong Woo Oh, Artem O. Denisov, Pengcheng Chen, Jason R. Petta
Summary: Silicon can be isotopically enriched for highly coherent semiconductor spin qubits, but the six-fold valley degeneracy in bulk Si may affect silicon quantum devices. A cryogen-free scanning gate microscope for Si/Si0.7Ge0.3 quantum devices at mK temperatures was developed, capable of forming and measuring quantum dots without compromising quantum control experiments. Vibration noise reduction techniques were implemented to achieve precise characterization of fully functioning Si/Si0.7Ge0.3 quantum devices.
Article
Multidisciplinary Sciences
Adam R. Mills, Charles R. Guinn, Michael J. Gullans, Anthony J. Sigillito, Mayer M. Feldman, Erik Nielsen, Jason R. Petta
Summary: Silicon spin qubits have the potential to become the dominant technology in the development of intermediate-scale quantum processors. However, there are still shortcomings in achieving high-fidelity state preparation and readout, as well as single- and two-qubit gate operations.
Article
Chemistry, Multidisciplinary
Artem O. Denisov, Seong W. Oh, Gordian Fuchs, Adam R. Mills, Pengcheng Chen, Christopher R. Anderson, Mark F. Gyure, Arthur W. Barnard, Jason R. Petta
Summary: Researchers have successfully combined the spatial resolution of scanning probe microscopy with the speed of microwave measurements by coupling a metallic tip to a Si/SiGe double quantum dot. They were able to observe excited states with an energy of -65microelectronvolts, consistent with valley splittings in Si/SiGe.
Article
Physics, Applied
A. R. Mills, C. R. Guinn, M. M. Feldman, A. J. Sigillito, M. J. Gullans, M. T. Rakher, J. Kerckhoff, C. A. C. Jackson, J. R. Petta
Summary: In this study, the researchers demonstrate that by operating with low electron temperatures and employing high-bandwidth cryogenic amplifiers, single-qubit readout visibilities of >99% and average single-qubit control fidelities of >99.95% can be achieved in silicon spin qubits, indicating high overall operation fidelity.
PHYSICAL REVIEW APPLIED
(2022)
Review
Physics, Multidisciplinary
Guido Burkard, Thaddeus D. Ladd, Andrew Pan, John M. Nichol, Jason R. Petta
Summary: The spin degree of freedom of an electron or a nucleus is a basic property that provides a natural two-level system for quantum information processing. Semiconductor spin qubits have made significant advancements in terms of quantum state preparation, coherent control, and measurement. These qubits have the potential for scalable solid-state quantum information processing, thanks to their small size, high density, long coherence times, and existing industrial infrastructure.
REVIEWS OF MODERN PHYSICS
(2023)
Article
Quantum Science & Technology
Artem O. Denisov, Gordian Fuchs, Seong W. Oh, Jason R. Petta
Summary: We charge floating metallic gates on a Si/SiGe heterostructure using the tip of an AFM. The AFM tip acts as a movable cryogenic switch, allowing us to bias and lock the charge on the gate. This method enables us to reduce the size of the quantum dot floating-gate electrode and measure immeasurable values of leakage resistance.
Article
Quantum Science & Technology
Jonas Mielke, Jason R. Petta, Guido Burkard
Summary: Nuclear spins exhibit long coherence times and strong isolation from the environment, making them promising for quantum information applications. A method for nuclear spin readout by probing microwave resonator transmission is presented, demonstrating feasibility with current state-of-the-art devices. Optimal readout points with strong signal contrast and potential for coherent excitation exchange between a nuclear spin qubit and cavity photons are identified.
Article
Quantum Science & Technology
F. Borjans, X. Zhang, X. Mi, G. Cheng, N. Yao, C. A. C. Jackson, L. F. Edge, J. R. Petta
Summary: The study found that the valley degree of freedom in silicon quantum dots is crucial for spin qubits. Significant variations in valley splitting and intra- and intervalley tunnel couplings were observed using microwave spectroscopy. Strong interactions between different valley states on neighboring dots were attributed to local inhomogeneities in the silicon quantum well.
Article
Materials Science, Multidisciplinary
Florian Ginzel, Adam R. Mills, Jason R. Petta, Guido Burkard
Article
Materials Science, Multidisciplinary
M. J. Gullans, J. R. Petta
Article
Physics, Multidisciplinary
X. Croot, X. Mi, S. Putz, M. Benito, F. Borjans, G. Burkard, J. R. Petta
PHYSICAL REVIEW RESEARCH
(2020)