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Phonons in solid-state quantum emitters play a crucial role in their performance as photon sources in quantum technology. For resonant driving, phonons dampen the Rabi oscillations resulting in reduced preparation fidelities. The phonon spectral density, which quantifies the strength of the carrier-phonon interaction, is non-monotonous as a function of energy. As one of the most prominent consequences, this leads to the reappearance of Rabi rotations for increasing pulse power, which was theoretically predicted in Phys. Rev. Lett. 98, 227403 (2007). In this paper we present the experimental demonstration of the reappearance of Rabi rotations.

The Multiple Sensor Interface is a simple sensor interface that works with USB, RS485 and GPIO. It allows one to make measurements using a variety of sensors based on the change of inductance, resistance, capacitance, and frequency using the same connector and same electronic interface circuit between the sensor and the microcontroller. The same device also provides some additional connectors for small voltage measurement. Any sensors used for the measurement of distinct phenomena can be used if the sensor output is based on inductance, resistance, capacitance or frequency within the measurement range of the device, obtaining a variable precision depending on the used sensor. The device presented is not meant for precise or accurate measurements. It is meant to be a reusable hardware that can be adapted/configured to a varied number of distinct situations, providing, to the user, more freedom in sensor selection as well as more options for device/system maintenance or reuse., Comment: 20 pages, 38 figures, personal project blog: https://multiple-sensor-interface.blogspot.com

Semiconductor devices are strong competitors in the race for the development of quantum com-putational systems. In this work, we interface two semiconductor building blocks of different di-mensionality and with complementary properties: (1) a quantum dot hosting a single exciton andacting as a nearly ideal single-photon emitter and (2) a quantum well in a 2D microcavity sustain-ing polaritons, which are known for their strong interactions and unique hydrodynamics propertiesincluding ultrafast real-time monitoring of their propagation and phase-mapping. In the presentexperiment we can thus observe how the injected single particles propagate and evolve inside themicrocavity, giving rise to hydrodynamics features typical of macroscopic systems despite their in-trinsic genuine quantum nature. In the presence of a structural defect, we observe the celebratedquantum interference of a single particle that produces fringes reminiscent of a wave propagation.While this behaviour could be theoretically expected, our imaging of such an interference pattern,together with a measurement of antibunching, constitutes the first demonstration of spatial mappingof the self-interference of a single quantum particle hitting an obstacle., Comment: 9 pages, 4 figures, supplementary 4 pages, 6 figures

Lattice matched GaAs/AlGaAs epitaxial structures with quantum dots are studied under static uniaxial stress applied either along the $[001]$ or $[110]$ crystal directions. We conduct simultaneous measurements of the spectral shifts in the photoluminescence of the bulk GaAs substrate, which relate to strain via deformation potentials $a$ and $b$, and the quadrupolar shifts in the optically detected nuclear magnetic resonance spectra of the quantum dots, which relate to the same strain via the gradient-elastic tensor $S_{ijkl}$. Measurements in two uniaxial stress configurations are used to derive the ratio $b/a=0.241\pm0.008$ in good agreement with previous studies on GaAs. Based on the previously estimated value of $a\approx-8.8$ eV we derive the product of the nuclear quadrupolar moment $Q$ and the $S$-tensor diagonal component in GaAs to be $QS_{11}\approx+0.76\times10^{-6}$ V for $^{75}$As and $QS_{11}\approx-0.37\times10^{-6}$ V for $^{69}$Ga nuclei. In our experiments the signs of $S_{11}$ are directly measurable, which was not possible in the earlier nuclear acoustic resonance studies. Our $QS_{11}$ values are a factor of $\sim$1.4 smaller than those derived from the nuclear acoustic resonance experiments [Phys. Rev. B 10, 4244 (1974)]. The gradient-elastic tensor values measured in this work can be applied in structural analysis of strained III-V semiconductor nanostructures via accurate modelling of their magnetic resonance spectra.

In this paper, we extend the results obtained by Cortes-Ferrero-Juriaans (2009) for the quaternion over the ring Colombeau's simplified generalized numbers, denoted by $\overline{\mathbb{H}}_s$, to the quaternion over the ring of Colombeau's full generalized numbers, denoted by $\overline{\mathbb{H}}$. In this paper, we introduce and investigate the topological algebra of the quaternion over the ring of Colombeau's full generalized numbers. This is an important object to study if one wants to build the algebraic theory of Colombeau's full generalized numbers $\overline{\mathbb{K}}$ studied by Aragona-Garcia-Juriaans (2013). We study some ring theoretical properties of $\overline{\mathbb{H}}$, we classify the dense ideals of $\overline{\mathbb{K}}$ in the algebraic sense, and as a consequence, it has a maximal ring of quotients which is Von Neumann regular., Comment: It is result of a research with second author who makes Postdoctoral Stage at UFCG with the third author with collaboration with the first author who work in UFRGS

The quantum entanglement measure is determined, for the first time, for a collection of spin-1/2 arranged in a infinite chain with finite temperature and applied to a single-crystal \beta-\mathrm{T_eVO_4}. The physical quantity proposed here to measure the entanglement is the distance between states by adopting the Hilbert-Schmidt norm. We relate the distance between states with the magnetic susceptibility. The decoherence temperature, above which the entanglement is suppressed, is determined for a system. A correlation among their decoherence temperatures and their respective exchange coupling constants is established, moreover, it is conjectured that the exchange coupling protects the system from decoherence as temperature increases.

The quantum entanglement measure is determined, for the first time, for antiferromagnetic trimer spin-1/2 Heisenberg chains. The physical quantity proposed to measure the entanglement is the distance between states by adopting the Hilbert-Schmidt norm. The method is applied to the new magnetic Cu(II) trimer system, 2b.3CuCl_2.2H_2O, and to the trinuclear Cu(II) halide salt, (3MAP)_2Cu_2Cl_8. The decoherence temperature, above which the entanglement is suppressed, is determined for the both systems. A correlation among their decoherence temperatures and their respective exchange coupling constants is established., Comment: 4 pages, 3 figures, two references were added, [9](S. Sahling et al., Nature Physics 11 (2015) 255) and [19](G. Toth, Phys.Rev.A 69 (2004) 052327)

Semi-insulating Gallium Arsenide (SI-GaAs) samples experimentally show, under high electric fields and even at room temperature, negative differential conductivity in N-shaped form (NNDC). Since the most consolidated model for n-GaAs, namely, "the model", proposed by E. Scholl was not capable to generate the NNDC curve for SI-GaAs, in this work we proposed an alternative model. The model proposed, "the two-valley model" is based on the minimal set of generation recombination equations for two valleys inside of the conduction band, and an equation for the drift velocity as a function of the applied electric field, that covers the physical properties of the nonlinear electrical conduction of the SI-GaAs system. The "two valley model" was capable to generate theoretically the NNDC region for the first time, and with that, we were able to build a high resolution parameter-space of the periodicity (PSP) using a Periodicity-Detection (PD) routine. In the parameter space were observed self-organized periodic structures immersed in chaotic regions. The complex regions are presented in a "shrimp" shape rotated around a focal point, which forms in large-scale a "snail shell" shape, with intricate connections between different "shrimps". The knowledge of detailed information on parameter spaces is crucial to localize wide regions of smooth and continuous chaos., Comment: 16 pages, 8 figures, Accepted for publication on International Journal of Bifurcation and Chaos (2015)

We investigate theoretically nonequilibrium quantum transport in a quantum dot attached to a Majorana bound state. Our approach is based on the Keldysh Green's function formalism, which allows us to investigate the electric current continuously from the zero-bias limit up to the large bias regime. In particular, our findings fully agree with previous results in the literature that calculate transport using linear response theory (zero-bias) or the master equation (high bias). Our $I-V$ curves reveal a characteristic slope given by $I=(G_{0}/2)V$ in linear response regime, where $G_0$ is the ballistic conductance $e^{2}/h$ as predicted in Phys. Rev. B 84, 201308(R) (2011). Deviations from this behavior is also discussed when the dot couples asymmetrically to both left and right leads. The differential conductance obtained from the left or the right currents can be larger or smaller than $G_{0}/2$ depending on the strength of the coupling asymmetry. In particular, the standard conductance derived from the Landauer-B\"{u}ttiker equation in linear response regime does not agree with the full nonequilibrium calculation, when the two leads couple asymmetrically to the quantum dot. We also compare the current through the quantum dot coupled to a regular fermionic (RF) zero-mode or to a Majorana bound state (MBS). The results differ considerably for the entire bias voltage range analyzed. Additionally, we observe the formation of a plateau in the characteristic $I-V$ curve for intermediate bias voltages when the dot is coupled to a MBS. Thermal effects are also considered. We note that when the temperature of the reservoirs is large enough both RF and MBS cases coincide for all bias voltages., Comment: 7 pages, 5 figures

We review the Inertial transformation and Lorentz transformation under a new context, by using Clifford Algebra or Geometric Algebra. The apparent contradiction between theses two approach is simply stems from different procedures for clock synchronization associated with different choices of the coordinates used to describe the physical world. We find the physical and coordinates components of both transformations. A important result is that in the case of Inertial transformation the physical components are exactly the Galilean transformations, but the speed of light is not c. Another interesting result is due to the fact the Lorentz transformations lead directly to physical components, and this case the speed of light is c. Finally e show that both scenarios, de-synchronization Einstein theory and synchronized theory, are all mathematically equivalent by means of Clifford Algebra Transformations.