197 research outputs found
Power dependence of electric dipole spin resonance
We develop a formalism of electric dipole spin resonance (EDSR) based on
slanting magnetic field, where we especially investigate the microwave
amplitude dependence. With increasing microwave amplitude, the Rabi frequency
increases linearly for a spin confined in a harmonic potential. How- ever, when
the spin is confined in the double-well potential, the Rabi frequency shows
sub-linear dependence with increasing the microwave amplitude.Comment: 4 pages, conference paper of APPC1
Wigner Functions for Arbitrary Quantum Systems
The possibility of constructing a complete, continuous Wigner function for
any quantum system has been a subject of investigation for over 50 years. A key
system that has served to illustrate the difficulties of this problem has been
an ensemble of spins. Here we present a general and consistent framework for
constructing Wigner functions exploiting the underlying symmetries in the
physical system at hand. The Wigner function can be used to fully describe any
quantum system of arbitrary dimension or ensemble size.Comment: 5 pages, 3 figure
Radiative corrections and quantum gates in molecular systems
We propose a method for quantum information processing using molecules
coupled to an external laser field. This utilizes molecular interactions,
control of the external field and an effective energy shift of the
doubly-excited state of two coupled molecules. Such a level shift has been seen
in the two-photon resonance experiments recently reported in Ref. [1]. Here we
show that this can be explained in terms of the QED Lamb shift. We quantify the
performance of the proposed quantum logic gates in the presence of dissipative
mechanisms. The unitary transformations required for performing one- and
two-qubit operations can be implemented with present day technology.Comment: 4 pages, 3 figures, Updated to correct important missing referenc
Resource Reduction in Multiplexed High-Dimensional Quantum Reed-Solomon Codes
Quantum communication technologies will play an important role in quantum
information processing in the near future as we network devices together.
However, their implementation is still a challenging task due to both loss and
gate errors. Quantum error correction codes are one important technique to
address this issue. In particular, the Quantum Reed-Solomon codes are known to
be quite efficient for quantum communication tasks. The high degree of physical
resources required, however, makes such a code difficult to use in practice. A
recent technique called quantum multiplexing has been shown to reduce resources
by using multiple degrees of freedom of a photon. In this work, we propose a
method to decompose multi-controlled gates using fewer gates via this
quantum multiplexing technique. We show that our method can significantly
reduce the required number of gates needed in the encoding circuits
for the quantum Reed-Solomon code. Our approach is also applicable to many
other quantum error correction codes and quantum algorithms, including Grovers
and quantum walks.Comment: 9 pages, 11 figure
Coherent dynamics amongst ensembles of spatially and spectrally varying emitters in waveguide QED
Spectrally and spatially varying ensembles of emitters embedded into
waveguide are ever-present in both well-established and emerging technologies.
If control of collective excitations can be attained, a plethora of coherent
quantum dynamics and applications may be realized on-chip in the scalable
paradigm of waveguide quantum electrodynamics (WQED). Here, we demonstrate how
inhomogeneous ensembles embedded into waveguides may be employed as single
effective and coherent emitters. The symmetric excitation of localized and
mescoscopic ensembles benefit from large collective waveguide coupling,
allowing for near-unity and tailorable non-Lorentzian extinction of waveguide
photons overcoming large inhomogeneous broadening. As an initial illustration
possible in currently existing experiments, we demonstrate the classic
recreation of the cavity QED (CQED) paradigm using ensembles of rare-earth ions
as coherent mirrors and qubits. This work introduces coherent ensemble dynamics
to WQED and extends the realm to spectrally tailorable emitters.Comment: 5 main text pages + 2 appendix pages. Comments welcome
Pennsylvania Folklife Vol. 29, No. 2
• The Landis Store Story • In This Place: Manheim 1866 • Kiss Me, I\u27m Italian : The Italian Market Festival, Philadelphia Photo Essay • A Century of Early American Children\u27s Books in German, 1738-1837 • Grange and Harvest Home Picnics in Chester County • Peter Muhlenberg Slept Here • Kartze G\u27dichte: Short Poemshttps://digitalcommons.ursinus.edu/pafolklifemag/1086/thumbnail.jp
Generation and processing of complex photon states with quantum frequency combs
The development of technologies for quantum information (QI) science demands the realization. and precise control of complex (multipartite and high dimensional) entangled systems on practical and scalable platforms. Quantum frequency combs (QFCs) represent a powerful tool towards this goal. They enable the generation of complex photon states within a single spatial mode as well as their manipulation using standard fiber-based telecommunication components. Here, we review recent progress in the development of QFCs, with a focus on results that highlight their importance for the realization of complex quantum states. In particular, we outline recent work on the use of integrated QFCs for the generation of high-dimensional multipartite optical cluster states - lying at the basis of measurement-based quantum computation. These results confirm that the QFC approach can provide a stable, practical, low-cost, and established platform for the development of quantum technologies, paving the way towards the advancement of QI science for out-of-the-lab applications, ranging from practical quantum computing to more secure communications
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