1,727 research outputs found
A highly efficient single photon-single quantum dot interface
Semiconductor quantum dots are a promising system to build a solid state
quantum network. A critical step in this area is to build an efficient
interface between a stationary quantum bit and a flying one. In this chapter,
we show how cavity quantum electrodynamics allows us to efficiently interface a
single quantum dot with a propagating electromagnetic field. Beyond the well
known Purcell factor, we discuss the various parameters that need to be
optimized to build such an interface. We then review our recent progresses in
terms of fabrication of bright sources of indistinguishable single photons,
where a record brightness of 79% is obtained as well as a high degree of
indistinguishability of the emitted photons. Symmetrically, optical
nonlinearities at the very few photon level are demonstrated, by sending few
photon pulses at a quantum dot-cavity device operating in the strong coupling
regime. Perspectives and future challenges are briefly discussed.Comment: to appear as a book chapter in a compilation "Engineering the
Atom-Photon Interaction" published by Springer in 2015, edited by A.
Predojevic and M. W. Mitchel
Nanocrystals in silicon photonic crystal standing-wave cavities as spin-photon phase gates for quantum information processing
By virtue of a silicon high-Q photonic crystal nanocavity, we propose and
examine theoretically interactions between a stationary electron spin qubit of
a semiconductor nanocrystal and a flying photon qubit. Firstly, we introduce,
derive and demonstrate for the first time the explicit conditions towards
realization of a spin-photon two-qubit phase gate, and propose these
interactions as a generalized quantum interface for quantum information
processing. Secondly, we examine novel single-spin-induced reflections as
direct evidence of intrinsic bare and dressed modes in our coupled
nanocrystal-cavity system. The excellent physical integration of this silicon
system provides tremendous potential for large-scale quantum information
processing
Quantum gate for Q switching in monolithic photonic bandgap cavities containing two-level atoms
Photonic bandgap cavities are prime solid-state systems to investigate
light-matter interactions in the strong coupling regime. However, as the cavity
is defined by the geometry of the periodic dielectric pattern, cavity control
in a monolithic structure can be problematic. Thus, either the state coherence
is limited by the read-out channel, or in a high Q cavity, it is nearly
decoupled from the external world, making measurement of the state extremely
challenging. We present here a method for ameliorating these difficulties by
using a coupled cavity arrangement, where one cavity acts as a switch for the
other cavity, tuned by control of the atomic transition.Comment: 6 pages, 5 figures, 1 tabl
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