Magneto-transport Spectroscopy of the First and Second Two-dimensional Subbands in Al0.25Ga0.75N/GaN Quantum Point Contacts

Lu, Fangchao; Tang, Ning; Shang, Liangliang; Guan, Haijing; Xu, Fujun; Ge, Weikun; Shen, Bo

doi:10.1038/srep42974

Cited by 4 publications

(3 citation statements)

References 18 publications

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“…2d) where a weak structure in the middle signals the QWS 2 . Our observation of QWS 2 is consistent with its recent detection via magneto-transport spectroscopy 24 . The presence of this state centered further away from the interface compared to the QWS 1 indicates that V(z) in the GaN-HEMTs has a long-range saturated shape (see the model in Fig.…”

Section: Resultssupporting

confidence: 92%

k-space imaging of anisotropic 2D electron gas in GaN/GaAlN high-electron-mobility transistor heterostructures

et al. 2018

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Nanostructures based on buried interfaces and heterostructures are at the heart of modern semiconductor electronics as well as future devices utilizing spintronics, multiferroics, topological effects, and other novel operational principles. Knowledge of electronic structure of these systems resolved in electron momentum k delivers unprecedented insights into their physics. Here we explore 2D electron gas formed in GaN/AlGaN high-electron-mobility transistor heterostructures with an ultrathin barrier layer, key elements in current high-frequency and high-power electronics. Its electronic structure is accessed with angle-resolved photoelectron spectroscopy whose probing depth is pushed to a few nanometers using soft-X-ray synchrotron radiation. The experiment yields direct k-space images of the electronic structure fundamentals of this system—the Fermi surface, band dispersions and occupancy, and the Fourier composition of wavefunctions encoded in the k-dependent photoemission intensity. We discover significant planar anisotropy of the electron Fermi surface and effective mass connected with relaxation of the interfacial atomic positions, which translates into nonlinear (high-field) transport properties of the GaN/AlGaN heterostructures as an anisotropy of the saturation drift velocity of the 2D electrons.

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Section: Resultssupporting

confidence: 92%

k-space imaging of anisotropic 2D electron gas in GaN/GaAlN high-electron-mobility transistor heterostructures

et al. 2018

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“…However, due to its relatively large value, the subband excitation energy is not easily accessible; see Ref. 35 for an example of its determination in a transport measurement. We illustrate these points in Fig.…”

Section: (α)mentioning

confidence: 99%

Orbital effects of a strong in-plane magnetic field on a gate-defined quantum dot

et al. 2019

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We theoretically investigate the orbital effects of an in-plane magnetic field on the spectrum of a quantum dot embedded in a two-dimensional electron gas (2DEG). We derive an effective twodimensional Hamiltonian where these effects enter in proportion to the flux penetrating the 2DEG. We quantify the latter in detail for harmonic, triangular, and square potential of the heterostructure. We show how the orbital effects allow one to extract a wealth of information, for example, on the heterostructure interface, the quantum dot size and orientation, and the spin-orbit fields. We illustrate the formalism by extracting this information from recent measured data [L. C. Camenzind, et al., arXiv:1804.00162; Nat. Commun. 9, 3454 (2018)]. arXiv:1804.00128v2 [cond-mat.mes-hall]

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“…[33][34][35][36][37] However, g-factor is not isotropic . 32,[38][39][40] Thus far, only a few conductance measurements in the presence of outof-plane magnetic fields are conducted to date , 36,[41][42][43][44][45][46][47][48] and there is a paucity of reports on double-layer QPCs. In the experiments above, enhancements in g-factor were reported that deserved theoretical attention .…”

Section: Introductionmentioning

confidence: 99%

Large Zeeman Splitting in Out-of-Plane Magnetic Field in a Double-Layer Quantum Point Contact

Terasawa,

Norimoto,

Arakawa

et al. 2021

Preprint

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In this study, we observe that the conductance of a quantum point contact on a GaAs/AlGaAs double quantum well depends significantly on the magnetic field perpendicular to the twodimensional electron gas. In the presence of the magnetic field, the subband edge splitting due to the Zeeman energy reaches 0.09 meV at 0.16 T, thereby suggesting an enhanced g-factor.The estimated g-factor enhancement is 17.5 times that of the bare value. It is considered that a low electron density and high mobility makes it possible to reach a strong many-body interaction regime in which this type of strong enhancement in g-factor can be observed.

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Magneto-transport Spectroscopy of the First and Second Two-dimensional Subbands in Al0.25Ga0.75N/GaN Quantum Point Contacts

Cited by 4 publications

References 18 publications

k-space imaging of anisotropic 2D electron gas in GaN/GaAlN high-electron-mobility transistor heterostructures

k-space imaging of anisotropic 2D electron gas in GaN/GaAlN high-electron-mobility transistor heterostructures

Orbital effects of a strong in-plane magnetic field on a gate-defined quantum dot

Large Zeeman Splitting in Out-of-Plane Magnetic Field in a Double-Layer Quantum Point Contact

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