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Related papers: Design rules for modulation-doped AlAs quantum wel…

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Beta-phase Ga2O3 has emerged as a promising candidate for a wide range of device applications, including power electronic devices, radio-frequency devices and solar-blind photodetectors. The wide bandgap energy and the predicted high…

In modern GaAs/Al$_x$Ga$_{1-x}$As heterostructures with record high mobilities, a two-dimensional electron gas (2DEG) in a quantum well is provided by two remote donor $\delta$-layers placed on both sides of the well. Each $\delta$-layer is…

Mesoscale and Nanoscale Physics · Physics 2018-10-10 M. Sammon , Tianran Chen , B. I. Shklovskii

We report on the growth and electrical characterization of a series of two-dimensional hole systems (2DHSs) used to study the density dependence of low temperature mobility in 20 nm GaAs/AlGaAs quantum wells. The hole density was controlled…

Mesoscale and Nanoscale Physics · Physics 2012-04-26 J. D. Watson , S. Mondal , G. Gardner , G. A. Csáthy , M. J. Manfra

We report quantum dots fabricated on very shallow 2-dimensional electron gases, only 30 nm below the surface, in undoped GaAs/AlGaAs heterostructures grown by molecular beam epitaxy. Due to the absence of dopants, an improvement of more…

Mesoscale and Nanoscale Physics · Physics 2015-03-19 W. Y. Mak , F. Sfigakis , K. Das Gupta , O. Klochan , H. E. Beere , I. Farrer , J. P. Griffiths , G. A. C. Jones , A. R. Hamilton , D. A. Ritchie

We present piezoresistance measurements in modulation doped AlAs quantum wells where the two-dimensional electron system occupies two conduction band valleys with elliptical Fermi contours. Our data demonstrate that, at low temperatures,…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Y. P. Shkolnikov , K. Vakili , E. P. De Poortere , M. Shayegan

Dilute arrays of GaAs/AlGaAs modulation-doped quantum dots (QDs) fabricated by electron-beam lithography and low impact reactive-ion etching exhibit highly homogeneous luminescence. Single quantum dots display spectral emission with peak…

Metal-oxide-semiconductor field-effect transistors (MOSFET's) using atomic-layer-deposited (ALD) Al$_2$O$_3$ as the gate dielectric are fabricated on the Si/Si$_{1-x}$Ge$_x$ heterostructures. The low-temperature carrier density of a…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 K. Lai , P. D. Ye , W. Pan , D. C. Tsui , S. A. Lyon , M. Muhlberger , F. Schaffler

In modern GaAs/Al$_x$Ga$_{1-x}$As heterostructures with record high mobilities, a two-dimensional electron gas (2DEG) in a quantum well is provided by two remote donor $\delta$-layers placed on both sides of the well. Each $\delta$-layer is…

Mesoscale and Nanoscale Physics · Physics 2018-07-16 M. Sammon , M. A. Zudov , B. I. Shklovskii

Two dimensional electron gases (2DEGs) realized at GaAs/AlGaAs single interfaces by molecular-beam epitaxy (MBE) reach mobilities of about 15 million cm^2/Vs if the AlGaAs alloy is grown after the GaAs. Surprisingly, the mobilities may drop…

We describe the growth of modulation-doped ZnSe/(Zn,Cd)Se quantum wells on (110) GaAs substrates. Unlike the well-known protocol for the epitaxy of ZnSe-based quantum structures on (001) GaAs, we find that the fabrication of quantum well…

We report on transport characteristics of field effect two-dimensional electron gases (2DEG) in surface indium antimonide quantum wells. The topmost 5 nm of the 30 nm wide quantum well is doped and shown to promote the formation of…

Mesoscale and Nanoscale Physics · Physics 2023-01-10 E. Annelise Bergeron , F. Sfigakis , Y. Shi , George Nichols , P. C. Klipstein , A. Elbaroudy , Sean M. Walker , Z. R. Wasilewski , J. Baugh

We report an experimental study of quantum conductivity corrections in a low mobility, high density two-dimensional electron gas in a AlGaAs/GaAs/AlGaAs quantum well in a wide temperature range (1.5K - 110K). This temperature range covers…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 V. T. Renard , I. V. Gornyi , O. A. Tkachenko , V. A. Tkachenko , Z. D. Kvon , E. B. Olshanetsky , A. I. Toropov , J. -C. Portal

We perform self-consistent Schr\"odinger-Poisson calculations with exchange and correlation corrections to determine the electron/hole gas in a radial hetero-junction formed in a modulation doped GaAs/AlGaAs core-multi-shell nanowire (CSNW)…

Mesoscale and Nanoscale Physics · Physics 2016-04-29 Andrea Bertoni , Miquel Royo , Farah Mahawish , Guido Goldoni

We have fabricated a device composed of two closely coupled two-dimensional electron systems, one of which resides within an AlAs quantum well (QW) at the X point of the Brillouin zone (BZ), while the other is contained at the $\Gamma$…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 E. P. De Poortere , M. Shayegan

By means of degenerate four-wave mixing (FWM), we investigate the quantum coherence of electron-hole pairs in the presence of a two-dimensional electron gas in modulation-doped GaAs-AlGaAs quantum wells in the quantum Hall effect regime.…

We demonstrate a method of making a very shallow, gateable, undoped 2-dimensional electron gas. We have developed a method of making very low resistivity contacts to these structures and systematically studied the evolution of the mobility…

Mesoscale and Nanoscale Physics · Physics 2021-09-17 W. Y. Mak , K. Das Gupta , H. E. Beere , I. Farrer , F. Sfigakis , D. A. Ritchie

Owing to their large effective mass, strong and tunable spin-orbit coupling, and complex band-structure, two-dimensional hole systems (2DHSs) in GaAs quantum wells provide rich platforms to probe exotic many-body physics, while also…

Mesoscale and Nanoscale Physics · Physics 2024-01-17 Adbhut Gupta , C. Wang , S. K. Singh , K. W. Baldwin , R. Winkler , M. Shayegan , L. N. Pfeiffer

Modulation-doped AlGaAs/GaAs heterostructures are utilized extensively in the study of quantum transport in nanostructures, but charge fluctuations associated with remote ionized dopants often produce deleterious effects. Electric…

Mesoscale and Nanoscale Physics · Physics 2015-06-19 Sumit Mondal , Geoffrey C. Gardner , John D. Watson , Saeed Fallahi , Amir Yacoby , Michael J. Manfra

The temperature driven flow lines of the Hall and dissipative magnetoconductance data (\sigma_{xy},\sigma_{xx}) are studied in the fractional quantum Hall regime for a 2D electron system in GaAs/Al_{x}Ga_{1-x}As heterostructures. The flow…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 S. S. Murzin , S. I. Dorozhkin , D. K. Maude , A. G. M. Jansen

Modulation-doped heterostructures are a key enabler for realizing high mobility and better scaling properties for high performance transistors. We report the realization of modulation-doped two-dimensional electron gas (2DEG) at…