4,034 research outputs found
Pseudo-digital quantum bits
Quantum computers are analog devices; thus they are highly susceptible to
accumulative errors arising from classical control electronics. Fast
operation--as necessitated by decoherence--makes gating errors very likely. In
most current designs for scalable quantum computers it is not possible to
satisfy both the requirements of low decoherence errors and low gating errors.
Here we introduce a hardware-based technique for pseudo-digital gate operation.
We perform self-consistent simulations of semiconductor quantum dots, finding
that pseudo-digital techniques reduce operational error rates by more than two
orders of magnitude, thus facilitating fast operation.Comment: 4 pages, 3 figure
Extended interface states enhance valley splitting in Si/SiO2
Interface disorder and its effect on the valley degeneracy of the conduction
band edge remains among the greatest theoretical challenges for understanding
the operation of spin qubits in silicon. Here, we investigate a
counterintuitive effect occurring at Si/SiO2 interfaces. By applying tight
binding methods, we show that intrinsic interface states can hybridize with
conventional valley states, leading to a large ground state energy gap. The
effects of hybridization have not previously been explored in details for
valley splitting. We find that valley splitting is enhanced in the presence of
disordered chemical bonds, in agreement with recent experiments.Comment: 4 pages, 4 figure
Extended interface states enhance valley splitting in Si/SiO2
Interface disorder and its effect on the valley degeneracy of the conduction
band edge remains among the greatest theoretical challenges for understanding
the operation of spin qubits in silicon. Here, we investigate a
counterintuitive effect occurring at Si/SiO2 interfaces. By applying tight
binding methods, we show that intrinsic interface states can hybridize with
conventional valley states, leading to a large ground state energy gap. The
effects of hybridization have not previously been explored in details for
valley splitting. We find that valley splitting is enhanced in the presence of
disordered chemical bonds, in agreement with recent experiments.Comment: 4 pages, 4 figure
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