Article
Chemistry, Physical
Nebile Isik Goktas, Vladimir G. Dubrovskii, Ray R. LaPierre
Summary: By adjusting the growth conditions of the InGaAs shell, different structural and morphological GaAs-InGaAs-GaAs core-shell-shell nanowire structures can be obtained. Increasing the In concentration in the InGaAs shell transitions the growth mode from preferential deposition at the NW base to the Stranski-Krastanov growth mode where InGaAs islands form along the NW length. Controlling the shell growth conditions can affect the optical properties and photoluminescence emission.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2021)
Article
Physics, Multidisciplinary
M. Solaimani, M. Izadifard
Summary: The study investigated the spin polarization efficiency and spin-dependent transmission of electrons passing through a multiple quantum well structure made of GaAs/Al0.3Ga0.7As. The number of wells in a constant total length was presented as a tuning tool for spin filtering purposes, with 100% spin polarization and spin-dependent transmission observed in some energy intervals.
INDIAN JOURNAL OF PHYSICS
(2021)
Article
Multidisciplinary Sciences
W. I. L. Lawrie, M. Rimbach-Russ, F. van Riggelen, N. W. Hendrickx, S. L. de Snoo, A. Sammak, G. Scappucci, J. Helsen, M. Veldhorst
Summary: As quantum processors scale up, the accurate characterization of errors due to crosstalks between qubits is important. This study presents a novel benchmarking protocol to analyze single-gate fidelities in a 2x2 hole spin qubit array in germanium. The results show high gate fidelities and robustness to crosstalk errors, providing crucial information for scaling up quantum information technology.
NATURE COMMUNICATIONS
(2023)
Article
Materials Science, Multidisciplinary
S. Anghel, A. Poshakinskiy, K. Schiller, F. Passmann, C. Ruppert, S. A. Tarasenko, G. Yusa, T. Mano, T. Noda, M. Betz
Summary: The study investigated the drift of electron spin helices in an external in-plane electric field in GaAs quantum wells using time-resolved magneto-optical Kerr microscopy. The results showed that the mobility of the electron gas locally decreases due to collisions with nonequilibrium holes, causing the spin helix drift to slow down at short delay times and higher excitation powers. However, as the delay times increase and the electrons and nonequilibrium holes are separated by an electric field, the spin helix drift accelerates and the mobility returns to its unperturbed value.
Article
Chemistry, Physical
Myles A. Steiner, Ryan M. France, Jeronimo Buencuerpo, John F. Geisz, Michael P. Nielsen, Andreas Pusch, Waldo J. Olavarria, Michelle Young, Nicholas J. Ekins-Daukes
Summary: High-efficiency solar cells are crucial for various applications, with lower energy bandgaps achieved through the use of multiple quantum wells. Incorporating strain-balanced GaAsP/GaInAs QWs into solar cells has led to increased efficiency.
ADVANCED ENERGY MATERIALS
(2021)
Article
Physics, Applied
S. Anghel, A. V. Poshakinskiy, K. Schiller, G. Yusa, T. Mano, T. Noda, M. Betz
Summary: This study investigates the correlation between spin diffusion, spin lifetime, and electron density in low-dimensional GaAs semiconductors. It reveals that the variation in the scattering rate with electron density is more important than fulfilling the persistent spin helix condition for achieving the longest spin lifetime. The experiment shows that the longest spin lifetime occurs at the transition from Boltzmann to Fermi-Dirac statistics for electron density.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Chemistry, Analytical
Satoshi Iba, Ryogo Okamoto, Koki Obu, Yuma Obata, Yuzo Ohno
Summary: The study revealed that under certain growth temperature conditions, the quality of GaAs/AlGaAs multiple quantum well structures is significantly improved, resulting in a significant increase in photoluminescence lifetime and electron spin relaxation time.
Article
Chemistry, Multidisciplinary
John A. Gil-Corrales, Alvaro L. Morales, Carlos A. Duque
Summary: In this study, the physics of a GaAs quantum well with AlGaAs barriers was characterized and analyzed based on an interior doped layer. Using the self-consistent method, the probability density, energy spectrum, and electronic density were analyzed by solving the Schrodinger, Poisson, and charge-neutrality equations. The system's response to geometric changes in well width and non-geometric changes in the doped layer's position, width, and donor density were reviewed. The finite difference method was used to solve all second-order differential equations. Finally, the optical absorption coefficient and electromagnetically induced transparency between the first three confined states were calculated using the obtained wave functions and energies, showing the potential for tunability through system geometry and doped-layer characteristics.
Article
Materials Science, Multidisciplinary
P. S. Alekseev, M. O. Nestoklon
Summary: In this study, it was found that the charge density of 2D electrons can significantly affect the Dresselhaus interaction in symmetric quantum wells. By internal electric field renormalization, this effect may play an important role in quantitative studies of spin-dependent phenomena in quantum wells.
Article
Physics, Multidisciplinary
J. Yoneda, J. S. Rojas-Arias, P. Stano, K. Takeda, A. Noiri, T. Nakajima, D. Loss, S. Tarucha
Summary: Research shows strong noise correlation between neighboring silicon spin qubits, with electric field fluctuations creating strongly correlated errors.
Article
Chemistry, Multidisciplinary
Xutao Yu, Yue Dai, Yanghua Lu, Chang Liu, Yanfei Yan, Runjiang Shen, Zunshan Yang, Lixuan Feng, Lijie Sun, Yong Liu, Shisheng Lin
Summary: The graphene/quantum wells/GaAs heterostructure solar cell shows high efficiency and high open-circuit voltage due to the carrier multiplication effect of graphene. The external quantum efficiency is improved in the heterostructure constructed by graphene/In0.15Ga0.85As/GaAs0.75P0.25 quantum wells, allowing more carriers to be effectively excited by higher energy photons through carrier multiplication effect.
Article
Nanoscience & Nanotechnology
Jarod Meyer, Aaron J. Muhowski, Leland Nordin, Eamonn Hughes, Brian Haidet, Daniel Wasserman, Kunal Mukherjee
Summary: The study focuses on photoluminescence in the mid-wave infrared range from strained thin films of rocksalt PbSe grown on GaAs substrates. Despite high dislocation densities, the films exhibit long minority carrier lifetimes and slow Shockley-Read-Hall recombination, indicating defect tolerance. The results suggest potential for high internal quantum efficiency in these films at room temperature.
Article
Physics, Applied
N. Dumoulin Stuyck, F. A. Mohiyaddin, R. Li, M. Heyns, B. Govoreanu, I. P. Radu
Summary: Using micromagnets for electron spin manipulation in silicon qubits is popular, but may introduce stray magnetic field gradients affecting qubits. By optimizing magnet design, dephasing effects can be minimized to improve qubit coherence times.
APPLIED PHYSICS LETTERS
(2021)
Article
Materials Science, Multidisciplinary
Ariel Khakshoor, Jeremy Belhassen, Michael Bendayan, Avi Karsenty
Summary: GaAs/GaAlAs/GaAs Asymmetric Quantum Wells (AQW) have multiple advantages in the domain of inter-sub-band transition (ISBT) and serve as the basic structures for advanced electro-optical devices. A new approach enables the creation and control of Self-Induced Electrical Fields (SIEF) by varying the dopant concentration in the structure.
RESULTS IN PHYSICS
(2022)
Article
Chemistry, Physical
Lubica Stuchlikova, Beata Sciana, Arpad Kosa, Matej Matus, Peter Benko, Juraj Marek, Martin Donoval, Wojciech Dawidowski, Damian Radziewicz, Martin Weis
Summary: Transient spectroscopies can detect charge carriers in semiconductor devices released from trapping centers and from quantum wells. Proper evaluation of material response to external stimuli requires knowledge of material properties, such as electron effective mass in complex structures.
Article
Physics, Applied
Pavel Sterin, Julia Wiegand, Jens Huebner, Michael Oestreich
PHYSICAL REVIEW APPLIED
(2018)
Article
Energy & Fuels
Robby Peibst, Michael Rienacker, Byungsul Min, Christina Klamt, Raphael Niepelt, Tobias F. Wieder, Thorsten Dullweber, Eduard Sauter, Jens Huebner, Michael Oestreich, Rolf Brendel
IEEE JOURNAL OF PHOTOVOLTAICS
(2019)
Article
Multidisciplinary Sciences
C. Hollemann, F. Haase, M. Rienaecker, V. Barnscheidt, J. Kruegener, N. Folchert, R. Brendel, S. Richter, S. Grosser, E. Sauter, J. Huebner, M. Oestreich, R. Peibst
SCIENTIFIC REPORTS
(2020)
Article
Chemistry, Physical
Andre Philipp Frauendorf, Andre Niebur, Lena Harms, Shivangi Shree, Bernhard Urbaszek, Michael Oestreich, Jens Huebner, Jannika Lauth
Summary: Wet-chemical synthesis methods have been shown to be promising for the straightforward solution-processing of quasi two-dimensional transition metal dichalcogenides (TMDs), with their photoluminescence properties virtually unexplored. This study demonstrates room temperature micro-PL of delicate ultrathin colloidal WS2 nanosheets synthesized from WCl6 and elemental sulfur, revealing comparable characteristics to exfoliated TMD monolayers and promising long-term air stability. These results suggest colloidal TMDs as easily synthesized and highly promising 2D semiconductors with optical properties fully competitive with conventionally fabricated ultrathin TMDs.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Physics, Applied
Tian-Jiao Sun, P. Sterin, L. Lengert, C. Nawrath, M. Jetter, P. Michler, Yang Ji, J. Huebner, M. Oestreich
Summary: This study investigates the spin and occupation noise of a single, positively charged (InGa)As quantum dot emitting photons in the telecommunication C-band. The results reveal insights into the hole-spin relaxation time, Auger recombination, and electron-spin relaxation time of the quantum dot, with comparable Auger recombination time to traditionally grown quantum dots emitting at shorter wavelengths.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Chemistry, Multidisciplinary
Lars F. Klepzig, Leon Biesterfeld, Michel Romain, Andre Niebur, Anja Schlosser, Jens Huebner, Jannika Lauth
Summary: This study demonstrated a direct synthesis route for 2D cubic rock salt structure PbSe nanoplatelets, with controllable lateral size tuning achieved by controlling temperature and adding octylamine. Post-synthetic treatment significantly improved the photoluminescence quantum yield of the PbSe nanoplatelets, while reducing the surface trap related PL contribution.
NANOSCALE ADVANCES
(2022)
Article
Chemistry, Multidisciplinary
Andre Niebur, Aljoscha Soell, Philipp Haizmann, Onno Strolka, Dominik Rudolph, Kevin Tran, Franz Renz, Andre Philipp Frauendorf, Jens Huebner, Heiko Peisert, Marcus Scheele, Jannika Lauth
Summary: 2D semiconducting transition metal dichalcogenides (TMDCs) show an ultrafast response to optical stimuli, making them highly promising for future optoelectronic applications. Colloidal nanochemistry is an emerging synthesis method for controlling the reaction and producing 2D TMDC nanosheets with small lateral sizes. In this study, the synthesis of 2D mono- and bilayer MoS2 nanoplatelets and MoS2 nanosheets was achieved by adjusting the molybdenum precursor concentration. The resulting MoS2 nanosheets underwent a transformation to the semiconducting crystal phase, showing potential for future colloidal photonics applications.
Article
Materials Science, Multidisciplinary
P. Sterin, L. Abaspour, J. G. Lonnemann, E. P. Rugeramigabo, J. Huebner, M. Oestreich
Summary: We present a detailed study of the temperature-dependent electron spin relaxation rate in n-type bulk GaAs and observe the longest spin relaxation time slightly below the metal-to-insulator transition at a finite temperature. This phenomenon results from the delicate interplay of hyperfine interaction, variable range hopping, and the Dyakonov-Perel mechanism.
Article
Materials Science, Multidisciplinary
L. Abaspour, P. Sterin, E. P. Rugeramigabo, J. Huebner, M. Oestreich
Article
Materials Science, Multidisciplinary
M. Beck, N. Abrosimov, J. Huebner, M. Oestreich
Article
Materials Science, Multidisciplinary
J. Wiegand, D. S. Smirnov, J. Osberghaus, L. Abaspour, J. Huebner, M. Oestreich
Article
Materials Science, Multidisciplinary
Julia Wiegand, Dmitry S. Smirnov, Jens Huebner, Mikhail M. Glazov, Michael Oestreich