001053087 001__ 1053087
001053087 005__ 20260202125356.0
001053087 037__ $$aFZJ-2026-01427
001053087 041__ $$aEnglish
001053087 1001_ $$0P:(DE-Juel1)195799$$aBuchhorn, Jonas$$b0$$eCorresponding author$$ufzj
001053087 1112_ $$aInternational Workshop on Hybrid Quantum Materials, Sciences, and Technologies 2025$$cMatsue$$d2025-10-27 - 2025-10-29$$gHQMST2025$$wJapan
001053087 245__ $$aOptimizing epitaxial growth of Bi2Te3 layers on sapphire towards high mobilities
001053087 260__ $$c2025
001053087 3367_ $$033$$2EndNote$$aConference Paper
001053087 3367_ $$2BibTeX$$aINPROCEEDINGS
001053087 3367_ $$2DRIVER$$aconferenceObject
001053087 3367_ $$2ORCID$$aCONFERENCE_POSTER
001053087 3367_ $$2DataCite$$aOutput Types/Conference Poster
001053087 3367_ $$0PUB:(DE-HGF)24$$2PUB:(DE-HGF)$$aPoster$$bposter$$mposter$$s1770029504_24250$$xAfter Call
001053087 520__ $$aSince the first proposal of creating Majorana bound states at the interface of a strong topological insulator and a superconductor [1], the interest in researching the properties of three-dimensional topological insulators has grown. Even though there were many different architectures for fault-tolerant Majorana-based quantum bits presented over the years [2-4], the two ingredients stayed the same, being a three dimensional topological insulator nanowire and a conventional s-wave superconductor. While there are several methods to prepare topological insulator thin films, molecular beam expitaxy promises to be the most scalable approach of creating pristine interfaces with the superconductor [5]. Therefore, in this work the method of epitaxially preparing topological insulators is employed. With various substrates available, we focused on sapphire substrates and worked on improving the growth of Bi2Te3, starting from optimizing the methods of chemical substrate cleaning, concluding in a sequence of Piranha solution and hydrofluoric acid etching. Further investigations were made to find an optimal Bi/Te atomic flux ratio in a Te-overpressure regime and a suitable substrate temperature, finally leading to twin-defect free crystals. We were aiming at high mobilities in cryogenic magnetotransport measurements in van der Pauw geometries, performed only hours after the crystal growth. All results are backed with X-ray diffraction analysis, showing correlations between crystal quality and electrical properties. Highest mobility samples show indications of significant surface transport of up to 40%, by Hall voltage non-linearities and by Shubnikov-de Haas oscillations revealing sheet carrier densities below 1⋅1012 cm-2. However, mobility values obtained by multi-channel Hall analysis and Dingle fits to quantum oscillations do differ by an order of magnitude, ranging from 2000 to 25000 cm2/Vs. This observation hints to a more complex explanation than classical multi-channel contributions from bulk and surface, like it was seen in cleaved bulk crystals in the past [6]. As the next step we plan to investigate the consistency of these anomalous effects and high mobilities from milli-/micrometer scale devices down to the nanometer regime, by ex-situ etching the material or using selective area epitaxy.	This work was supported by JST within ASPIRE for rising scientists.[1] L. Fu, C. L. Kane, Phys. Rev. Lett. 100 096407 (2010).[2] S. Plugge et al., New J. Phys. 19 012001 (2017).[3] C. Schrade, L. Fu, Phys. Rev. Lett. 121, 267002 (2018).[4] R. Aguado, L. P. Kouwenhoven, Physics Today 73 (6), 44-50 (2020).[5] P. Schüffelgen, D. Rosenbach, C. Li, et al., Nat. Nanotechnol. 14, 825-831 (2019).[6] D.-X. Qu et al., Science 329, 821-824 (2010).
001053087 536__ $$0G:(DE-HGF)POF4-5222$$a5222 - Exploratory Qubits (POF4-522)$$cPOF4-522$$fPOF IV$$x0
001053087 536__ $$0G:(GEPRIS)491798118$$aDFG project G:(GEPRIS)491798118 - Magnetische topologische Isolatoren für robuste Majorana Zustände (491798118)$$c491798118$$x1
001053087 536__ $$0G:(GEPRIS)390534769$$aDFG project G:(GEPRIS)390534769 - EXC 2004: Materie und Licht für Quanteninformation (ML4Q) (390534769)$$c390534769$$x2
001053087 65027 $$0V:(DE-MLZ)SciArea-120$$2V:(DE-HGF)$$aCondensed Matter Physics$$x0
001053087 65017 $$0V:(DE-MLZ)GC-120-2016$$2V:(DE-HGF)$$aInformation and Communication$$x0
001053087 7001_ $$0P:(DE-Juel1)171826$$aJalil, Abdur Rehman$$b1$$ufzj
001053087 7001_ $$0P:(DE-Juel1)125588$$aGrützmacher, Detlev$$b2$$ufzj
001053087 7001_ $$0P:(DE-Juel1)128634$$aSchäpers, Thomas$$b3$$ufzj
001053087 8564_ $$uhttps://jointquantum2025.jp/
001053087 909CO $$ooai:juser.fz-juelich.de:1053087$$pVDB
001053087 9101_ $$0I:(DE-588b)5008462-8$$6P:(DE-Juel1)195799$$aForschungszentrum Jülich$$b0$$kFZJ
001053087 9101_ $$0I:(DE-588b)5008462-8$$6P:(DE-Juel1)171826$$aForschungszentrum Jülich$$b1$$kFZJ
001053087 9101_ $$0I:(DE-588b)5008462-8$$6P:(DE-Juel1)125588$$aForschungszentrum Jülich$$b2$$kFZJ
001053087 9101_ $$0I:(DE-588b)5008462-8$$6P:(DE-Juel1)128634$$aForschungszentrum Jülich$$b3$$kFZJ
001053087 9131_ $$0G:(DE-HGF)POF4-522$$1G:(DE-HGF)POF4-520$$2G:(DE-HGF)POF4-500$$3G:(DE-HGF)POF4$$4G:(DE-HGF)POF$$9G:(DE-HGF)POF4-5222$$aDE-HGF$$bKey Technologies$$lNatural, Artificial and Cognitive Information Processing$$vQuantum Computing$$x0
001053087 920__ $$lyes
001053087 9201_ $$0I:(DE-Juel1)PGI-9-20110106$$kPGI-9$$lHalbleiter-Nanoelektronik$$x0
001053087 9201_ $$0I:(DE-Juel1)PGI-10-20170113$$kPGI-10$$lJARA Institut Green IT$$x1
001053087 980__ $$aposter
001053087 980__ $$aVDB
001053087 980__ $$aI:(DE-Juel1)PGI-9-20110106
001053087 980__ $$aI:(DE-Juel1)PGI-10-20170113
001053087 980__ $$aUNRESTRICTED