Chronic Meningitis Due to Otitis Media With Cholesteatoma in a Five-Year-Old Child With a Cochlear Implant.

Cochlear implants (CIs) restore hearing in patients with severe-to-profound deafness. Post-CI meningitis is a rare but redoubted complication. We present the case of a five-year-old CI recipient who experienced an episode of chronic meningitis caused by chronic otitis media with cholesteatoma encasing the electrode lead. We hypothesize that the cholesteatoma led to an ascending infection to the cochlea, passing through the labyrinths, resulting in chronic meningitis. Although positive neural responses were initially noted on cochlear electrical stimulation, these responses resolved a few weeks after reimplantation. Our report highlights the importance of careful otoscopic examination and diagnostic work-up in patients presenting with otogenic meningitis to rule out cholesteatoma formation and to ensure prompt surgical exploration if warranted.

Chronic Meningitis Due to Otitis Media With Cholesteatoma in a Five-Year-Old Child With a Cochlear Implant

Cochlear implants (CIs) restore hearing in patients with severe-to-profound deafness. Post-CI meningitis is a rare but redoubted complication. We present the case of a five-year-old CI recipient who experienced an episode of chronic meningitis caused by chronic otitis media with cholesteatoma encasing the electrode lead. We hypothesize that the cholesteatoma led to an ascending infection to the cochlea, passing through the labyrinths, resulting in chronic meningitis. Although positive neural responses were initially noted on cochlear electrical stimulation, these responses resolved a few weeks after reimplantation. Our report highlights the importance of careful otoscopic examination and diagnostic work-up in patients presenting with otogenic meningitis to rule out cholesteatoma formation and to ensure prompt surgical exploration if warranted.

Injection laryngoplasty for laryngeal cleft type I in an 8-week-old infant.

A laryngeal cleft is a rare anatomical deformity which is increasingly treated with injection laryngoplasty. Since diagnosis of laryngeal cleft type I is often made between 2 and 5 years of age, this treatment is rarely performed on very young children. In this case, we describe how injection laryngoplasty is performed safely on an 8-week-old child, and we illustrate its added value for the diagnostic process and for temporary symptom relief.

Randomized benchmarking of multiqubit gates.

We describe an extension of single-qubit gate randomized benchmarking that measures the error of multiqubit gates in a quantum information processor. This platform-independent protocol evaluates the performance of Clifford unitaries, which form a basis of fault-tolerant quantum computing. We implemented the benchmarking protocol with trapped ions and found an error per random two-qubit Clifford unitary of 0.162±0.008, thus setting the first benchmark for such unitaries. By implementing a second set of sequences with an extra two-qubit phase gate inserted after each step, we extracted an error per phase gate of 0.069±0.017. We conducted these experiments with transported, sympathetically cooled ions in a multizone Paul trap-a system that can in principle be scaled to larger numbers of ions.

Coherent diabatic ion transport and separation in a multizone trap array.

We investigate the dynamics of single and multiple ions during transport between and separation into spatially distinct locations in a multizone linear Paul trap. A single 9Be+ ion in a ~2 MHz harmonic well was transported 370 µm in 8 µs, corresponding to 16 periods of oscillation, with a gain of 0.1 motional quanta. Similar results were achieved for the transport of two ions. We also separated chains of up to 9 ions from one potential well to two distinct potential wells. With two ions this was accomplished in 55 µs, with excitations of approximately two quanta for each ion. Fast transport and separation can significantly reduce the time overhead in certain architectures for scalable quantum information processing with trapped ions.

Entangled mechanical oscillators.

Hallmarks of quantum mechanics include superposition and entanglement. In the context of large complex systems, these features should lead to situations as envisaged in the 'Schrödinger's cat' thought experiment (where the cat exists in a superposition of alive and dead states entangled with a radioactive nucleus). Such situations are not observed in nature. This may be simply due to our inability to sufficiently isolate the system of interest from the surrounding environment-a technical limitation. Another possibility is some as-yet-undiscovered mechanism that prevents the formation of macroscopic entangled states. Such a limitation might depend on the number of elementary constituents in the system or on the types of degrees of freedom that are entangled. Tests of the latter possibility have been made with photons, atoms and condensed matter devices. One system ubiquitous to nature where entanglement has not been previously demonstrated consists of distinct mechanical oscillators. Here we demonstrate deterministic entanglement of separated mechanical oscillators, consisting of the vibrational states of two pairs of atomic ions held in different locations. We also demonstrate entanglement of the internal states of an atomic ion with a distant mechanical oscillator. These results show quantum entanglement in a degree of freedom that pervades the classical world. Such experiments may lead to the generation of entangled states of larger-scale mechanical oscillators, and offer possibilities for testing non-locality with mesoscopic systems. In addition, the control developed here is an important ingredient for scaling-up quantum information processing with trapped atomic ions.

New measurement of the electron magnetic moment and the fine structure constant.

A measurement using a one-electron quantum cyclotron gives the electron magnetic moment in Bohr magnetons, g/2=1.001 159 652 180 73 (28) [0.28 ppt], with an uncertainty 2.7 and 15 times smaller than for previous measurements in 2006 and 1987. The electron is used as a magnetometer to allow line shape statistics to accumulate, and its spontaneous emission rate determines the correction for its interaction with a cylindrical trap cavity. The new measurement and QED theory determine the fine structure constant, with alpha{-1}=137.035 999 084 (51) [0.37 ppb], and an uncertainty 20 times smaller than for any independent determination of alpha.

New measurement of the electron magnetic moment using a one-electron quantum cyclotron.

A new measurement resolves cyclotron and spin levels for a single-electron quantum cyclotron to obtain an electron magnetic moment, given by g/2=1.001 159 652 180 85 (76) [0.76 ppt]. The uncertainty is nearly 6 times lower than in the past, and g is shifted downward by 1.7 standard deviations. The new g, with a quantum electrodynamics (QED) calculation, determines the fine structure constant with a 0.7 ppb uncertainty--10 times smaller than for atom-recoil determinations. Remarkably, this 100 mK measurement probes for internal electron structure at 130 GeV.

New determination of the fine structure constant from the electron value and QED.

Quantum electrodynamics (QED) predicts a relationship between the dimensionless magnetic moment of the electron (g) and the fine structure constant (alpha). A new measurement of g using a one-electron quantum cyclotron, together with a QED calculation involving 891 eighth-order Feynman diagrams, determine alpha(-1)=137.035 999 710 (96) [0.70 ppb]. The uncertainties are 10 times smaller than those of nearest rival methods that include atom-recoil measurements. Comparisons of measured and calculated g test QED most stringently, and set a limit on internal electron structure.

Single-particle self-excited oscillator.

Electronic feedback is used to self-excite the axial oscillation of a single electron in a Penning trap. Large, stable, easily detected oscillations arise even in an anharmonic potential. Amplitudes are controlled by adjusting the feedback gain, and frequencies can be made nearly independent of amplitude fluctuations. Quantum jump spectroscopy of a perpendicular cyclotron motion reveals the absolute temperature and amplitude of the self-excited oscillation. The possibility to quickly measure parts per billion frequency shifts could open the way to improved measurements of e(-), e(+), p, and (-)p magnetic moments.