Electron dephasing in wurtzite indium nitride thin films

Jia, Zheng; Shen, Wei; Ogawa, Hiroshi; Guo, Qi

doi:10.1063/1.2400097

Cited by 9 publications

(9 citation statements)

References 19 publications

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“…This flux cancellation should result in a broadening of the weak antilocalization peak and consequently to an overestimated value of ␣ in the fit to the Kettemann model. This probably also explains why the spin-orbit scattering time so = l so 2 / D of 0.33ϫ 10 −12 s obtained in our experiment is lower than the value of 1.3 ϫ 10 −12 s found by Jia et al 29 for InN thin films. Remarkably, in our nanowires no suppression of weak antilocalization is observed as it was found in narrow wires based on planar two-dimensional electron gases.…”

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confidence: 55%

Spin-orbit coupling and phase-coherent transport in InN nanowires

Petersen¹,

Hernandez²,

Calarco³

et al. 2009

Phys. Rev. B

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The low-temperature quantum transport properties of gated InN nanowires were investigated. Magneticfield-dependent as well as gate-dependent measurements of universal conductance fluctuations were performed to gain information on the phase coherence in the electron transport. We found a pronounced decrease in the variance of the conductance by about a factor of 2 in gate-dependent fluctuation measurements if a magnetic field is applied. This effect is explained by the suppression of the Cooperon channel of the electron correlation contributing to the conductance fluctuations. Despite the fact that the diameter of the nanowire is less than 100 nm a clear weak antilocalization effect is found in the averaged magnetoconductance being in strong contrast to the suppression of weak antilocalization for narrow quantum wires based on planar two-dimensional electron gases. The unexpected robustness of the weak antilocalization effect observed here is attributed to the tubular topology of the surface electron gas in InN nanowires. DOI: 10.1103/PhysRevB.80.125321 PACS number͑s͒: 73.23.Ϫb, 72.15.Rn, 73.63.Nm Semiconductor nanowires fabricated by a bottom-up approach are not only interesting for the realization of future nanoscaled devices 1,2 but also appear to be very attractive model systems to tackle fundamental questions concerning the transport in strongly confined systems. [3][4][5] In order to avoid the problem connected with carrier depletion, narrowband gap semiconductors, i.e., InAs or InN, 1,6,7 are preferred. The underlying reason is that here the Fermi-level pinning in the conduction band results in a carrier accumulation at the surface. In fact, the tubular topology of the surface electron gas opens up the possibility to observe unconventional quantum transport phenomena. 7 When the phase-coherence length l in the nanowire is comparable to its dimensions the conductance fluctuates if a magnetic field is applied or if the electron concentration is changed by means of a gate electrode. [8][9][10] These so-called universal conductance fluctuations being in the order of e 2 / h originate from the fact that in small disordered samples, electron interference effects are not averaged out. 11,12 Here, we analyzed universal conductance fluctuations to study the quantum transport properties in InN nanowires. In contrast to previous investigations 6,7,9,10 the successful preparation of a top-gate electrode allowed us to study universal conductance fluctuations not only as a function of magnetic field but also as a function of gate voltage. Since InN is a narrow band gap semiconductor, one naturally expects spinorbit coupling effects similar to the case of InAs. 13 Because this phenomena is of importance for spin electronic applications, we devoted special attention to the open question if spin-orbit coupling is present in InN nanowires. In transport measurements information on the spin-orbit coupling can be gained from the analysis of the characteristic beating pattern in Shubnikov-de Haas oscillations 14 or by study...

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confidence: 55%

Spin-orbit coupling and phase-coherent transport in InN nanowires

Petersen¹,

Hernandez²,

Calarco³

et al. 2009

Phys. Rev. B

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“…More importantly, such a surface accumulation layer can serve as a homogeneous layer, instead of using a heterojunction, for injecting spin-polarized electrons to the bulk semiconductor with high spin injection efficiency. To date, Rashba spin splitting has been reported in quantum wells and other heterostructures based on InN − and InAs, − however, there is no experimental report of the spin splitting in surface electron accumulation layer on either of the two materials due to the difficulty in manipulating the surface band bending.…”

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confidence: 99%

Tunable Surface Electron Spin Splitting with Electric Double-Layer Transistors Based on InN

et al. 2013

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Electrically manipulating electron spins based on Rashba spin-orbit coupling (SOC) is a key pathway for applications of spintronics and spin-based quantum computation. Two-dimensional electron systems (2DESs) offer a particularly important SOC platform, where spin polarization can be tuned with an electric field perpendicular to the 2DES. Here, by measuring the tunable circular photogalvanic effect (CPGE), we present a room-temperature electric-field-modulated spin splitting of surface electrons on InN epitaxial thin films that is a good candidate to realize spin injection. The surface band bending and resulting CPGE current are successfully modulated by ionic liquid gating within an electric double-layer transistor configuration. The clear gate voltage dependence of CPGE current indicates that the spin splitting of the surface electron accumulation layer is effectively tuned, providing a way to modulate the injected spin polarization in potential spintronic devices.

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“…A clear weak antilocalization effect 18 was found in the averaged magnetoconductance indicating the presence of spin-orbit coupling. 19 The latter effect is important for spin manipulation in nanoscale spintronic devices. The unexpected robustness of the weak antilocalization effect observed in narrow InN wires gives evidence that the tubular topology of the surface electron gas in InN nanowires is maintained also at very small dimensions.…”

Section: Inn Nanowiresmentioning

confidence: 99%