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Utilizing a novel carbon doping source, we prepared two-dimensional hole gases in a symmetric quantum well structure in the GaAs/AlGaAs heterosystem. Low temperature hole mobilities up to 1.2 x 10^6 cm^2/Vs at a density of 2.3 x 10^11 cm^-2…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 C. Gerl , S. Schmult , H. - P. Tranitz , C. Mitzkus , W. Wegscheider

We demonstrate that coupled AlGaN/GaN quantum wells with asymmetric widths ($L_1-L_2<30 $ A achieve up to 4.5 times higher mobility than single wells at optimal separation (d = 100 A). Crucially, mobility surpasses single wells when d>40 A…

Mesoscale and Nanoscale Physics · Physics 2025-08-05 Le Tri Dat , Tran Trong Tai , Truong Van Tuan , Vo Van Tai , Nguyen Duy Vy

We report the observation of fractional quantum Hall (FQH) effects in a two-dimensional electron gas (2DEG) confined to an InAs/AlGaSb quantum well, using a dual-gated Hall-bar device allowing for the independent control of the vertical…

Mesoscale and Nanoscale Physics · Physics 2022-02-17 S. Komatsu , H. Irie , T. Akiho , T. Nojima , T. Akazaki , K. Muraki

Quasi-two-dimensional electron systems (q-2DES) are formed in various hetero-structures, including oxide interfaces. Oxygen vacancies (OVs) in oxides like $\mathrm{SrTiO_3}$ are known to produce electronic carriers. A novel way to produce…

Mesoscale and Nanoscale Physics · Physics 2022-07-27 Shyam Sundar Yadav , Shelender Kumar , Pankaj Kumar , Ananth Venkatesan

We present the fabrication details of completely undoped electron-hole bilayer devices in a GaAs/AlGaAs double quantum well heterostructure with a 30 nm barrier. These devices have independently tunable densities of the two-dimensional…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 J. A. Seamons , D. R. Tibbetts , J. L. Reno , M. P. Lilly

We report on the achievement of a two-dimensional electron gas in completely undoped In[0.75]Al[0.25]As/In[0.75]Ga[0.25]As metamorphic quantum wells. Using these structures we were able to reduce the carrier density, with respect to…

Materials Science · Physics 2009-11-10 F. Capotondi , G. Biasiol , I. Vobornik , L. Sorba , F. Giazotto , A. Cavallini , B. Fraboni

Shallow GaAs/InGaAs/GaAs quantum well structures with and without a three monolayer thick AlAs central barrier have been investigated for different well widths and Si doping levels. The transport parameters are determined by resistivity…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 V. A. Kulbachinskii , I. S. Vasil'evskii , R. A. Lunin , G. Galistu , A. de Visser , G. B. Galiev , S. S. Shirokov , V. G. Mokerov

Motivated by recent breakthrough in molecular beam epitaxy of GaAs/AlGaAs quantum wells [Y. J. Chung \textit{et al.}, Nature Materials \textbf{20}, 632 (2021)], we examine contributions to mobility and quantum mobility from various…

Mesoscale and Nanoscale Physics · Physics 2022-06-30 Yi Huang , B. I. Shklovskii , M. A. Zudov

Quantum well of AlGaAs/GaAs is very important to study transport properties of electrons due to its wider application in electronic devices. Hence, the double well of AlGaAs/GaAs with triple barrier is taken to study transmission…

Mesoscale and Nanoscale Physics · Physics 2025-02-20 Krishna Rana Magar , Upendra Rijal , Sanju Shrestha

Equilibrium properties of electrons in double-heterojunction AlGaAs/GaAs\AlGaAs structures are investigated theoretically, using a full self-consistent numerical method. The transition from single to bilayer electron systems is discussed…

Condensed Matter · Physics 2016-08-31 L. Smrcka , T. Jungwirth

Understanding the non-monotonic behavior in the temperature dependent resistance, R(T), of strongly correlated two-dimensional (2D) carriers in clean semiconductors has been a central issue in the studies of 2D metallic states and…

Mesoscale and Nanoscale Physics · Physics 2015-01-27 Nicholas J. Goble , John D. Watson , Michael J. Manfra , Xuan P. A. Gao

Scaling down the GaN channel in a double heterostructure AlGaN/GaN/AlGaN High Electron Mobility Transistor (HEMT) to the thicknesses on the order of or even smaller than the Bohr radius confines electrons in the quantum well even at low…

Mesoscale and Nanoscale Physics · Physics 2023-11-28 G. Simin , M. Shur

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

We report on the growth and electrical characterization of modulation-doped Al0.24Ga0.76As/AlxGa1-xAs/Al0.24Ga0.76As quantum wells with mole fractions as low as x=0.00057. Such structures will permit detailed studies of the impact of alloy…

Mesoscale and Nanoscale Physics · Physics 2013-07-02 Geoffrey C. Gardner , John D. Watson , Sumit Mondal , Nianpei Deng , Gabor A. Csáthy , Michael J. Manfra

Quantum wells constitute one of the most important classes of devices in the study of 2D systems. In a double layer QW, the additional "which-layer" degree of freedom gives rise to celebrated phenomena such as Coulomb drag, Hall drag and…

For several decades now, ultra-high-mobility GaAs two-dimensional electron systems (2DESs) have served as the hallmark platform for various branches of research in condensed matter physics. Fundamental to this long-standing history of…

Mesoscale and Nanoscale Physics · Physics 2022-08-26 Yoon Jang Chung , A. Gupta , K. W. Baldwin , K. W. West , M. Shayegan , L. N. Pfeiffer

We report on the transport properties of a high mobility two-dimensional hole system (2DHS) confined in GaAs/AlGaAs quantum wells grown molecular-beam epitaxy on the (100) surface of GaAs. The quantum wells are modulation-doped with carbon…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 M. J. Manfra , L. N. Pfeiffer , K. W. West , R. de Picciotto , K. W. Baldwin

We report a detailed study of the influence of the electron-electron interaction on physical observables (conductance, etc.) of a disordered electron liquid in double quantum well heterostructure. We find that even in the case of common…

Mesoscale and Nanoscale Physics · Physics 2011-08-23 I. S. Burmistrov , I. V. Gornyi , K. S. Tikhonov

The complex band structure, large spin-orbit induced band splitting, and heavy effective mass of two-dimensional (2D) hole systems hosted in GaAs quantum wells render them rich platforms to study many-body physics and ballistic transport…

Mesoscale and Nanoscale Physics · Physics 2022-03-22 Yoon Jang Chung , C. Wang , S. K. Singh , A. Gupta , K. W. Baldwin , K. W. West , R. Winkler , M. Shayegan , L. N. Pfeiffer

We report results of investigations of structural and transport properties of GaAs/Ga(1-x)In(x)As/GaAs quantum wells (QWs) having a 0.5-1.8 ML thick Mn layer, separated from the QW by a 3 nm thick spacer. The structure has hole mobility of…