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QUROPE - aggregated feeds in category PhysicsenarXiv.org: Quantum Physics: Quantum Error Correction with the Semion Code. (arXiv:1810.08204v1 [quant-ph])
http://arxiv.org/abs/1810.08204
<p>We present a full quantum error correcting procedure with the semion code: an
off-shell extension of the double semion model. We construct open strings
operators that recover the quantum memory from arbitrary errors and closed
string operators that implement the basic logical operations for information
processing.<p><a href="http://arxiv.org/abs/1810.08204">read more</a></p>
Mon, 22 Oct 2018 13:34:05 +0200arXiv.org: Quantum Physics: Many-particle interference to test Born's rule. (arXiv:1810.08221v1 [quant-ph])
http://arxiv.org/abs/1810.08221
<p>Born's rule, one of the cornerstones of quantum mechanics, relates detection
probabilities to the modulus square of the wave function. Single-particle
interference is accordingly limited to pairs of quantum paths and higher-order
interferences are prohibited. Deviations from Born's law have been quantified
via the Sorkin parameter which is proportional to the third-order term. We here
extend this formalism to many-particle interferences and find that they exhibit
a much richer structure.<p><a href="http://arxiv.org/abs/1810.08221">read more</a></p>
Mon, 22 Oct 2018 13:34:05 +0200arXiv.org: Quantum Physics: Efficient indirect control of nuclear spins in diamond NV centers. (arXiv:1810.08230v1 [quant-ph])
http://arxiv.org/abs/1810.08230
<p>Hybrid quantum registers consisting of different types of qubits offer a
range of advantages as well as challenges. The main challenge is that some
types of qubits react only slowly to external control fields, thus considerably
slowing down the information processing operations. Here, we propose and
demonstrate an indirect control scheme that allows us to control the nuclear
spins of an NV center indirectly, by control operations applied to the electron
spin, combined with free precession under the anisotropic hyperfine
interaction.<p><a href="http://arxiv.org/abs/1810.08230">read more</a></p>
Mon, 22 Oct 2018 13:34:05 +0200arXiv.org: Quantum Physics: Conclusive Precision Bounds for SU(1,1) Interferometers. (arXiv:1810.08242v1 [quant-ph])
http://arxiv.org/abs/1810.08242
<p>In this paper, we revisit the quantum Fisher information (QFI) calculation in
SU(1,1) interferometer considering different phase configurations. When one of
the input modes is a vacuum state, we show by using phase averaging, different
phase configurations give same QFI. In addition, by casting the phase
estimation as a two-parameter estimation problem, we show that the calculation
of the quantum Fisher information matrix (QFIM) is necessary in general.
Particularly, within this setup, the phase averaging method is equivalent to a
two parameter estimation problem.<p><a href="http://arxiv.org/abs/1810.08242">read more</a></p>
Mon, 22 Oct 2018 13:34:05 +0200arXiv.org: Quantum Physics: Infrared laser magnetometry with a NV doped diamond intracavity etalon. (arXiv:1810.08253v1 [physics.optics])
http://arxiv.org/abs/1810.08253
<p>We propose an hybrid laser system consisting of a semiconductor external
cavity laser associated to an intra-cavity diamond etalon doped with
nitrogen-vacancy color centers.<p><a href="http://arxiv.org/abs/1810.08253">read more</a></p>
Mon, 22 Oct 2018 13:34:05 +0200arXiv.org: Quantum Physics: Atomically-thin quantum dots integrated with lithium niobate photonic chips. (arXiv:1810.08254v1 [physics.app-ph])
http://arxiv.org/abs/1810.08254
<p>The electro-optic, acousto-optic and nonlinear properties of lithium niobate
make it a highly versatile material platform for integrated quantum photonic
circuits. A prerequisite for quantum technology applications is the ability to
efficiently integrate single photon sources, and to guide the generated photons
through ad-hoc circuits. Here we report the integration of quantum dots in
monolayer WSe2 into a Ti in-diffused lithium niobate directional coupler.<p><a href="http://arxiv.org/abs/1810.08254">read more</a></p>
Mon, 22 Oct 2018 13:34:05 +0200arXiv.org: Quantum Physics: Spectra of ultrabroadband squeezed pulses and the finite-time Unruh-Davies effect. (arXiv:1810.08273v1 [quant-ph])
http://arxiv.org/abs/1810.08273
<p>We study spectral properties of quantum radiation of ultimately short
duration. In particular, we introduce a continuous multimode squeezing operator
for the description of subcycle pulses of entangled photons generated by a
coherent-field driving in a thin nonlinear crystal with second order
susceptibility. We find the ultrabroadband spectra of the emitted quantum
radiation perturbatively in the strength of the driving field. These spectra
can be related to the spectra expected in an Unruh-Davies experiment with a
finite time of acceleration.<p><a href="http://arxiv.org/abs/1810.08273">read more</a></p>
Mon, 22 Oct 2018 13:34:05 +0200arXiv.org: Quantum Physics: Quantum computing from a mathematical perspective: a description of the quantum circuit model. (arXiv:1810.08277v1 [quant-ph])
http://arxiv.org/abs/1810.08277
<p>This paper is an essentially self-contained and rigorous description of the
fundamental principles of quantum computing from a mathematical perspective. It
is intended to help mathematicians who want to get a grasp of this quickly
growing discipline and find themselves taken aback by the language gap between
mathematics and the pioneering fields on the matter: computer science and
quantum physics.
</p>Mon, 22 Oct 2018 13:34:05 +0200arXiv.org: Quantum Physics: Qubit Allocation for Noisy Intermediate-Scale Quantum Computers. (arXiv:1810.08291v1 [quant-ph])
http://arxiv.org/abs/1810.08291
<p>In the era of noisy-intermediate-scale quantum computers, we expect to see
quantum devices with increasing numbers of qubits emerge in the foreseeable
future. To practically run quantum programs, logical qubits have to be mapped
to the physical qubits by a qubit allocation algorithm. However, on present day
devices, qubits differ by their error rate and connectivity. Here, we establish
and demonstrate on current experimental devices a new allocation algorithm that
combines the simulated annealing method with local search of the solution space
using Dijkstra's algorithm.<p><a href="http://arxiv.org/abs/1810.08291">read more</a></p>
Mon, 22 Oct 2018 13:34:05 +0200arXiv.org: Quantum Physics: Strong entanglement criterion involving momentum weak values. (arXiv:1810.08296v1 [quant-ph])
http://arxiv.org/abs/1810.08296
<p>In recent years weak values have been used to explore interesting quantum
features in novel ways. In particular, the real part of the weak value of the
momentum operator has been widely studied, mainly in connection with (nonlocal)
Bohmian trajectories. Here we focus on the imaginary part and its role in
relation with the entanglement of a bipartite system. We establish an
entanglement criterion based on weak momentum correlations, that allows to
discern whether the entanglement is encoded in the amplitude and/or in the
phase of the wave function.<p><a href="http://arxiv.org/abs/1810.08296">read more</a></p>
Mon, 22 Oct 2018 13:34:05 +0200