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Related papers: Valley Degeneracies in (111) Silicon Quantum Wells

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Due to degeneracies arising from crystal symmetries, it is possible for electron states at band edges ("valleys") to have additional spin-like quantum numbers. An important question is whether coherent manipulation can be performed on such…

Electron spin qubits in Si/SiGe quantum wells are limited by the small and variable energy separation of the conduction band valleys. While sharp quantum well interfaces are pursued to increase the valley splitting energy deterministically,…

The energies of valley-orbit states in silicon quantum dots are determined by an as yet poorly understood interplay between interface roughness, orbital confinement, and electron interactions. Here, we report measurements of one- and…

Valleytronics is rapidly emerging as an exciting area of basic and applied research. In two dimensional systems, valley polarisation can dramatically modify physical properties through electron-electron interactions as demonstrated by such…

The authors investigate the magnetic field dependence of the energy splitting between low-lying valley states for electrons in a Si/SiGe quantum well tilted with respect to the crystallographic axis. The presence of atomic steps at the…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Mark Friesen , M. A. Eriksson , S. N. Coppersmith

Monolayer valley semiconductors, such as tungsten diselenide (WSe$_2$), possess valley pseudospin degrees of freedom that are optically addressable but degenerate in energy. Lifting the energy degeneracy by breaking time-reversal symmetry…

Using polarization-resolved photoluminescence spectroscopy, we investigate valley degeneracy breaking by out-of-plane magnetic field in back-gated monolayer MoSe$_2$ devices. We observe a linear splitting of $-0.22…

Mesoscale and Nanoscale Physics · Physics 2015-02-03 David MacNeill , Colin Heikes , Kin Fai Mak , Zachary Anderson , Andor Kormányos , Viktor Zólyomi , Jiwoong Park , Daniel C. Ralph

In Si(111) crystals, a strong biaxial tensile strain applied within the (111) plane is considered to shift the lowest energy point of the conduction band from the $\Delta$ valley to the L valley. Electrons confined in this L valley…

Quantum Physics · Physics 2026-04-16 Takafumi Tokunaga , Hiromichi Nakazato

Using quantum Monte Carlo simulations we have mapped out the zero temperature phase diagram of a symmetric electron-hole bilayer with twofold valley degeneracy, as function of the interlayer distance $d$ and in-layer density $n$. We find…

Strongly Correlated Electrons · Physics 2023-02-08 Stefania De Palo , F. Tramonto , Saverio Moroni , Gaetano Senatore

The coherent manipulation of spin and pseudospin underlies existing and emerging quantum technologies, including NMR, quantum communication, and quantum computation. Valley polarization, associated with the occupancy of degenerate, but…

Mesoscale and Nanoscale Physics · Physics 2017-02-01 Ziliang Ye , Dezheng Sun , Tony F. Heinz

We study the cross-section shape and size effects on the valley splitting in PbSe nanowires within the framework of empirical $sp^3d^5s^*$ tight-binding method. We consider ideallized prismatic nanowires, grown along [110], with the…

Mesoscale and Nanoscale Physics · Physics 2019-05-22 Ivan Avdeev

We have investigated the valley splitting of two-dimensional electrons in high quality Si/Si$_{1-x}$Ge$_x$ heterostructures under tilted magnetic fields. For all the samples in our study, the valley splitting at filling factor $\nu=3$…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 K. Lai , T. M. Lu , W. Pan , D. C. Tsui , S. Lyon , J. Liu , Y. H. Xie , M. Muhlberger , F. Schaffler

Ab-initio calculations of nuclear masses, the binding energy and the $\alpha$ decay half-lives are intractable for heavy nucleus, because of the curse of dimensionality in many body quantum simulations as proton number($\mathrm{N}$) and…

Nuclear Theory · Physics 2022-06-29 Chen-Qi Li , Chao-Nan Tong , Hong-Jing Du , Long-Gang Pang

Lifting the valley degeneracy is an efficient way to achieve valley polarization for further valleytronics operations. In this work, we demonstrate that a large valley splitting can be obtained in monolayer transition metal dichalcogenides…

Materials Science · Physics 2018-01-17 Lei Xu , Ming Yang , Lei Shen , Jun Zhou , Tao Zhu , Yuan Ping Feng

The electronic structure for a strained Si/SiGe quantum well grown on a tilted substrate with periodic steps is calculated using a parameterized tight-binding method. For a zero tilt angle the energy difference between the two lowest minima…

Materials Science · Physics 2007-05-23 Paul von Allmen , Seungwon Lee

Degenerate minima in momentum space - valleys - provide an additional degree of freedom that can be used for information transport and storage. Notably, such minima naturally exist in the band structure of transition metal dichalcogenides…

Recent models of the decay out of superdeformed bands can broadly be divided into two categories. One approach is based on the similarity between the tunneling process involved in the decay and that involved in the fusion of heavy ions, and…

Nuclear Theory · Physics 2009-11-11 A. N. Wilson , A. J. Sargeant , P. M. Davidson , M. S Hussein

Decay of the superdeformed bands have been studied mainly concentrating upon the decay-out spin, which is sensitive to the tunneling probability between the super- and normal-deformed wells. Although the basic features are well understood…

Nuclear Theory · Physics 2009-11-06 Y. R. Shimizu , M. Matsuo , K. Yoshida

We present here results of atomistic theory of electrons confined by metallic gates in a single layer of transition metal dichalcogenides. The electronic states are described by the tight-binding model and computed using a computational box…

Mesoscale and Nanoscale Physics · Physics 2020-01-22 Maciej Bieniek , Ludmila Szulakowska , Pawel Hawrylak

Masses of superheavy (SH) nuclei with $Z=98-128$, including odd and odd-odd nuclei, are systematically calculated within the microscopic-macroscopic model based on the deformed Woods-Saxon potential. Ground states are found by minimizing…

Nuclear Theory · Physics 2015-06-18 P. Jachimowicz , M. Kowal , J. Skalski