5 research outputs found
All-Electrical Quantum Computation with Mobile Spin Qubits
We describe and discuss a solid state proposal for quantum computation with
mobile spin qubits in one-dimensional systems, based on recent advances in
spintronics. Static electric fields are used to implement a universal set of
quantum gates, via the spin-orbit and exchange couplings. Initialization and
measurement can be performed either by spin injection from/to ferromagnets, or
by using spin filters and mesoscopic spin polarizing beam-splitters. The
vulnerability of this proposal to various sources of error is estimated by
numerical simulations. We also assess the suitability of various materials
currently used in nanotechnology for an actual implementation of our model.Comment: 10 pages, 6 figs, RevTeX
Modeling Single Electron Transfer in Si:P Double Quantum Dots
Solid-state systems such as P donors in Si have considerable potential for
realization of scalable quantum computation. Recent experimental work in this
area has focused on implanted Si:P double quantum dots (DQDs) that represent a
preliminary step towards the realization of single donor charge-based qubits.
This paper focuses on the techniques involved in analyzing the charge transfer
within such DQD devices and understanding the impact of fabrication parameters
on this process. We show that misalignment between the buried dots and surface
gates affects the charge transfer behavior and identify some of the challenges
posed by reducing the size of the metallic dot to the few donor regime.Comment: 11 pages, 7 figures, submitted to Nanotechnolog
Bell inequalities and entanglement in solid state devices
Bell-inequality checks constitute a probe of entanglement -- given a source
of entangled particles, their violation are a signature of the non-local nature
of quantum mechanics. Here, we study a solid state device producing pairs of
entangled electrons, a superconductor emitting Cooper pairs properly split into
the two arms of a normal-metallic fork with the help of appropriate filters. We
formulate Bell-type inequalities in terms of current-current cross-correlators,
the natural quantities measured in mesoscopic physics; their violation provides
evidence that this device indeed is a source of entangled electrons.Comment: 4 pages, 1 figur