58 research outputs found
Two-dimensional cavity grid for scalable quantum computation with superconducting circuits
Superconducting circuits are among the leading contenders for quantum
information processing. This promising avenue has been strengthened with the
advent of circuit quantum electrodynamics, underlined by recent experiments
coupling on-chip microwave resonators to superconducting qubits. However,
moving towards more qubits will require suitable novel architectures. Here, we
propose a scalable setup for quantum computing where such resonators are
arranged in a two-dimensional grid with a qubit at each intersection. Its
versatility allows any two qubits on the grid to be coupled at a swapping
overhead independent of their distance and yields an optimal balance between
reducing qubit transition frequency spread and spurious cavity-induced
couplings. These features make this setup unique and distinct from existing
proposals in ion traps, optical lattices, or semiconductor spins. We
demonstrate that this approach encompasses the fundamental elements of a
scalable fault-tolerant quantum computing architecture.Comment: version as published in EPL 95 No 5 (March 2009) 50007, 5 page
Hybrid Mechanical Systems
We discuss hybrid systems in which a mechanical oscillator is coupled to
another (microscopic) quantum system, such as trapped atoms or ions,
solid-state spin qubits, or superconducting devices. We summarize and compare
different coupling schemes and describe first experimental implementations.
Hybrid mechanical systems enable new approaches to quantum control of
mechanical objects, precision sensing, and quantum information processing.Comment: To cite this review, please refer to the published book chapter (see
Journal-ref and DOI). This v2 corresponds to the published versio
Quantum Transduction of Telecommunications-band Single Photons from a Quantum Dot by Frequency Upconversion
The ability to transduce non-classical states of light from one wavelength to
another is a requirement for integrating disparate quantum systems that take
advantage of telecommunications-band photons for optical fiber transmission of
quantum information and near-visible, stationary systems for manipulation and
storage. In addition, transducing a single-photon source at 1.3 {\mu}m to
visible wavelengths for detection would be integral to linear optical quantum
computation due to the challenges of detection in the near-infrared. Recently,
transduction at single-photon power levels has been accomplished through
frequency upconversion, but it has yet to be demonstrated for a true
single-photon source. Here, we transduce the triggered single-photon emission
of a semiconductor quantum dot at 1.3 {\mu}m to 710 nm with a total detection
(internal conversion) efficiency of 21% (75%). We demonstrate that the 710 nm
signal maintains the quantum character of the 1.3 {\mu}m signal, yielding a
photon anti-bunched second-order intensity correlation, g^(2)(t), that shows
the optical field is composed of single photons with g^(2)(0) = 0.165 < 0.5.Comment: 7 pages, 4 figure
Laser cooling of a nanomechanical oscillator into its quantum ground state
A patterned Si nanobeam is formed which supports co-localized acoustic and
optical resonances that are coupled via radiation pressure. Starting from a
bath temperature of T=20K, the 3.68GHz nanomechanical mode is cooled into its
quantum mechanical ground state utilizing optical radiation pressure. The
mechanical mode displacement fluctuations, imprinted on the transmitted cooling
laser beam, indicate that a final phonon mode occupancy of 0.85 +-0.04 is
obtained.Comment: 18 pages, 10 figure
Retail Demand for Voluntary Carbon Offsets – A Choice Experiment Among Swiss Consumers
π‐Extended Polyaromatic Hydrocarbons by Sustainable Alkyne Annulations through Double C−H/N−H Activation
Investigation of temperature dependence of dielectric relaxation in liquid water by THz reflection spectroscopy and molecular dynamics simulation
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