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Investigation on the two-dimensional electron gas in in as quantum wells coupled to epitaxial aluminum for exploration of topological superconductivity
Investigation on the two-dimensional electron gas in in as quantum wells coupled to epitaxial aluminum for exploration of topological superconductivity
상세정보
- 자료유형
- 학위논문 서양
- 최종처리일시
- 20250211152049
- ISBN
- 9798342106207
- DDC
- 621.795
- 저자명
- Zhang, Teng.
- 서명/저자
- Investigation on the two-dimensional electron gas in in as quantum wells coupled to epitaxial aluminum for exploration of topological superconductivity
- 발행사항
- [Sl] : Purdue University, 2024
- 발행사항
- Ann Arbor : ProQuest Dissertations & Theses, 2024
- 형태사항
- 138 p
- 주기사항
- Source: Dissertations Abstracts International, Volume: 86-04, Section: B.
- 주기사항
- Advisor: Manfra, Michael J.;Greene, Christopher H.;Banerjee, Arnab;Vayrynen, Jukka I.
- 학위논문주기
- Thesis (Ph.D.)--Purdue University, 2024.
- 초록/해제
- 요약The two-dimensional electron gas (2DEG) in shallow InAs quantum wells, combined with epitaxial aluminum, is commonly used to study topological superconductivity. Key features include strong spin-orbit coupling, a high effective g-factor, and the ability to manage proximity-induced superconductivity. My thesis discusses two aspects of this unique material. In the first section, I report on the transport characteristics of shallow InGaAs/InAs/InGaAs quantum wells and evaluate the effect of modulation doping on these shallow InAs quantum well structures. We systematically investigate the magnetotransport properties in relation to doping density and spacer thickness. Optimized samples show peak mobilities exceeding 100,000 cm2/Vs at n2DEG 1012 cm-2in gated Hall bar, marking the highest mobility observed in this type of heterostructure. Our findings suggest that the doping layer moves the electron wave function away from the surface, minimizing surface scattering and enhancing mobility. This mobility improvement does not compromise Rashba spin-orbit coupling or induced superconductivity. In the second section, motivated by a theoretical study by Peng et al., we explore tunneling spectroscopy measurements on DC current biased planar Josephson junctions made on an undoped hybrid epitaxial Al-InAs 2DEG heterostructure. We observe four tunneling conductance peaks in the spectroscopy that can be adjusted by DC current bias. Our analysis indicates that these results come from strong coupling between the tunneling probe and the superconducting leads, rather than from Floquet engineering. We also touch on potential improvements to the device's design and materials. This work lays the groundwork for further investigation of Floquet physics in planar Josephson junctions. This thesis ends with a discussion of other unusual physics that could be explored in these novel shallow InAs quantum wells coupled with epitaxial aluminum.
- 일반주제명
- Etching
- 일반주제명
- Crystal structure
- 일반주제명
- Aluminum
- 일반주제명
- Molecular beam epitaxy
- 일반주제명
- Energy
- 일반주제명
- Electrons
- 일반주제명
- Superconductivity
- 일반주제명
- Nanowires
- 일반주제명
- Spectrum analysis
- 일반주제명
- Semiconductors
- 일반주제명
- Magnetic fields
- 일반주제명
- Microscopy
- 일반주제명
- Analytical chemistry
- 일반주제명
- Atomic physics
- 일반주제명
- Electromagnetics
- 일반주제명
- Low temperature physics
- 일반주제명
- Nanotechnology
- 일반주제명
- Optics
- 기타저자
- Purdue University.
- 기본자료저록
- Dissertations Abstracts International. 86-04B.
- 전자적 위치 및 접속
- 로그인 후 원문을 볼 수 있습니다.
MARC
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■00520250211152049
■006m o d
■007cr#unu||||||||
■020 ▼a9798342106207
■035 ▼a(MiAaPQ)AAI31345257
■035 ▼a(MiAaPQ)Purdue25669182
■040 ▼aMiAaPQ▼cMiAaPQ
■0820 ▼a621.795
■1001 ▼aZhang, Teng.
■24510▼aInvestigation on the two-dimensional electron gas in in as quantum wells coupled to epitaxial aluminum for exploration of topological superconductivity
■260 ▼a[Sl]▼bPurdue University▼c2024
■260 1▼aAnn Arbor▼bProQuest Dissertations & Theses▼c2024
■300 ▼a138 p
■500 ▼aSource: Dissertations Abstracts International, Volume: 86-04, Section: B.
■500 ▼aAdvisor: Manfra, Michael J.;Greene, Christopher H.;Banerjee, Arnab;Vayrynen, Jukka I.
■5021 ▼aThesis (Ph.D.)--Purdue University, 2024.
■520 ▼aThe two-dimensional electron gas (2DEG) in shallow InAs quantum wells, combined with epitaxial aluminum, is commonly used to study topological superconductivity. Key features include strong spin-orbit coupling, a high effective g-factor, and the ability to manage proximity-induced superconductivity. My thesis discusses two aspects of this unique material. In the first section, I report on the transport characteristics of shallow InGaAs/InAs/InGaAs quantum wells and evaluate the effect of modulation doping on these shallow InAs quantum well structures. We systematically investigate the magnetotransport properties in relation to doping density and spacer thickness. Optimized samples show peak mobilities exceeding 100,000 cm2/Vs at n2DEG 1012 cm-2in gated Hall bar, marking the highest mobility observed in this type of heterostructure. Our findings suggest that the doping layer moves the electron wave function away from the surface, minimizing surface scattering and enhancing mobility. This mobility improvement does not compromise Rashba spin-orbit coupling or induced superconductivity. In the second section, motivated by a theoretical study by Peng et al., we explore tunneling spectroscopy measurements on DC current biased planar Josephson junctions made on an undoped hybrid epitaxial Al-InAs 2DEG heterostructure. We observe four tunneling conductance peaks in the spectroscopy that can be adjusted by DC current bias. Our analysis indicates that these results come from strong coupling between the tunneling probe and the superconducting leads, rather than from Floquet engineering. We also touch on potential improvements to the device's design and materials. This work lays the groundwork for further investigation of Floquet physics in planar Josephson junctions. This thesis ends with a discussion of other unusual physics that could be explored in these novel shallow InAs quantum wells coupled with epitaxial aluminum.
■590 ▼aSchool code: 0183.
■650 4▼aEtching
■650 4▼aCrystal structure
■650 4▼aAluminum
■650 4▼aMolecular beam epitaxy
■650 4▼aEnergy
■650 4▼aElectrons
■650 4▼aSuperconductivity
■650 4▼aNanowires
■650 4▼aSpectrum analysis
■650 4▼aSemiconductors
■650 4▼aMagnetic fields
■650 4▼aMicroscopy
■650 4▼aAnalytical chemistry
■650 4▼aAtomic physics
■650 4▼aElectromagnetics
■650 4▼aLow temperature physics
■650 4▼aNanotechnology
■650 4▼aOptics
■690 ▼a0791
■690 ▼a0486
■690 ▼a0748
■690 ▼a0607
■690 ▼a0598
■690 ▼a0652
■690 ▼a0752
■71020▼aPurdue University.
■7730 ▼tDissertations Abstracts International▼g86-04B.
■790 ▼a0183
■791 ▼aPh.D.
■792 ▼a2024
■793 ▼aEnglish
■85640▼uhttp://www.riss.kr/pdu/ddodLink.do?id=T17162745▼nKERIS▼z이 자료의 원문은 한국교육학술정보원에서 제공합니다.


