SiGe band engineering for MOS, CMOS and quantum effect devices

Wang, K. L.; Thomas, S.G.; Tanner, M. O.

doi:10.1007/bf00125886

Cited by 42 publications

(22 citation statements)

References 74 publications

(58 reference statements)

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“…12 The mismatch is completely accommodated by uniform lattice strain and the interatomic distances parallel to the interfacial plane, i.e. the "effective" lattice constants in the plane, remain equal to the equilibrium value of the substrate material.…”

Section: Theoretical Approach a Strain In Si Layersmentioning

confidence: 99%

Strain effects on silicon donor exchange: Quantum computer architecture considerations

2002

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Proposed Silicon-based quantum computer architectures have attracted attention because of their promise for scalability and their potential for synergetically utilizing the available resources associated with the existing infrastructure of the powerful Si technology. Quantitative understanding of and precise physical control over donor (e.g. Phosphorus) exchange are crucial elements in the physics underlying the proposed Si-based quantum computer hardware. An important potential problem in this context is that inter-valley interference originating from the degeneracy in the Si conduction band edge causes fast oscillations in donor exchange coupling, which imposes significant constraints on the Si quantum computer architecture. In this paper we consider the effect of external strain on Si donor exchange in the context of quantum computer hardware. We study donor electron exchange in uniaxially strained Si, since strain partially lifts the valley degeneracy in the bulk. In particular, we focus on the effects of donor displacements among lattice sites on the exchange coupling, investigating whether inter-valley interference poses less of a problem to exchange coupling of donors in strained Si. We show, using the Kohn-Luttinger envelope function approach, that fast oscillations in exchange coupling indeed disappear for donor pairs that satisfy certain conditions for their relative positions, while in other situations the donor exchange coupling remains oscillatory, with periods close to interatomic spacing. We also comment on the possible role of controlled external strain in the design and fabrication of Si quantum computer architecture.

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Section: Theoretical Approach a Strain In Si Layersmentioning

confidence: 99%

Strain effects on silicon donor exchange: Quantum computer architecture considerations

2002

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“…The resultant two dimensional carrier gas may enhance their motilities and therefore device performance. 1 For this reason, Ge-based ͑such as GeMn͒ diluted magnetic semiconductors ͑DMSs͒, compatible with the current Si technology, have been studied extensively. [2][3][4][5][6][7][8][9][10][11][12][13] It is well understood that the low solubility of Mn in Ge has been a main barrier to achieve a high T c DMS GeMn film with high Mn concentration and uniformly distributed Mn in Ge.…”

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confidence: 99%

Tadpole shaped Ge0.96Mn0.04 magnetic semiconductors grown on Si

Wang

Xiu

Zou

et al. 2010

Applied Physics Letters

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Magnetic and structural properties of a Ge0.96Mn0.04 thin film grown on Si has been investigated by transmission electron microscopy and superconducting quantum interference device. Tadpole shaped coherent GeMn clusters induced by spinodal decomposition were revealed in the film. Although these coherent clusters are dominant, Mn5Ge3 precipitates can be still detectable, contributing to a complex ferromagnetism. The Ge buffer layer, by relieving the misfit strain between Si and Ge, can significantly reduce the density of lattice defects in the subsequent GeMn layer. Our findings unveil a particular morphology of GeMn clusters, which would contribute to better understand the GeMn system.

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“…Among them, (Ga,Mn)As became the first and the mostly studied DMSs since 1996 (Lu and Lieber, 2006); but to our knowledge, some studies lacked the threshold doping profile to push its curie temperature to room temperature and above (currently around 190 K (Lyu and Moon, 2003, van der Meulen et al, 2008, Maekawa, 2006, Wang et al, 1995). Since then, substantial research has been carried out in III-V and II-VI semiconductors to improve the T c by increasing the solubility limit and meanwhile minimizing self-compensation effect of magnetic structures, using radical techniques such as delta doping of modulation doped quantum structures (Bhatt et al, 2002, Cho et al, 2008, Berciu and Bhatt, 2001, Lauhon et al, 2002.…”

Section: Introductionmentioning

confidence: 99%