Impacts of isotope ion mass on trapped-electron-mode (TEM)-driven turbulence and zonal flows in magnetically confined fusion plasmas are investigated. Gyrokinetic simulations of TEM-driven turbulence in three-dimensional magnetic configuration of helical plasmas with hydrogen isotope ions and real-mass kinetic electrons are realized for the first time, and the linear and the nonlinear nature of the isotope and collisional effects on the turbulent transport and zonal-flow generation are clarified. It is newly found that combined effects of the collisional TEM stabilization by the isotope ions and the associated increase in the impacts of the steady zonal flows at the near-marginal linear stability lead to the significant transport reduction with the opposite ion mass dependence in comparison to the conventional gyro-Bohm scaling. The universal nature of the isotope effects on the TEM-driven turbulence and zonal flows is verified for a wide variety of toroidal plasmas, e.g., axisymmetric tokamak and non-axisymmetric helical or stellarator systems.

We investigate the elastic buckling of a triangular prism made of a soft elastomer. A face of the prism is bonded to a stiff slab that imposes an average axial compression. We observe two possible buckling modes which are localized along the free ridge. For ridge angles $\varphi$ below a critical value ${\varphi }^{\star }\approx 90°$, experiments reveal an extended sinusoidal mode, while for $\varphi$ above ${\varphi }^{\star }$, we observe a series of creases progressively invading the lateral faces starting from the ridge. A numerical linear stability analysis is set up using the finite-element method and correctly predicts the sinusoidal mode for $\varphi \le {\varphi }^{\star }$, as well as the associated critical strain ${\epsilon }_c(\varphi )$. The experimental transition at ${\varphi }^{\star }$ is found to occur when this critical strain ${\epsilon }_c(\varphi )$ attains the value ${\epsilon }_c({\varphi }^{\star })=0.44$ corresponding to the threshold of the subcritical surface creasing instability. Previous analyses have focused on elastic crease patterns appearing on planar surfaces, where the role of scale invariance has been emphasized; our analysis of the elastic ridge provides a different perspective, and reveals that scale invariance is not a sufficient condition for localization.

If you mix lines and circles, what happens at the edge of the mixture? The problem is simply stated, but the answer is not obvious. Twenty years ago it was proposed that a universal topological driving force would drive cyclic chains to enrich the surface of blends of linear and cyclic chains. Here such behavior is demonstrated experimentally for sufficiently long chains and the limit in molecular weight where packing effects dominate over the topological driving force is identified.

The relative modification of the prompt $\psi (2S)$ and $J/\psi$ yields from $pp$ to PbPb collisions, at the center-of-mass energy of 5.02 TeV per nucleon pair, is presented. The analysis is based on $pp$ and PbPb data samples collected by the CMS experiment at the LHC in 2015, corresponding to integrated luminosities of $28.0{\mathrm{pb}}^{-1}$ and $464\mu {\mathrm{b}}^{-1}$, respectively. The double ratio of measured yields of prompt charmonia reconstructed through their decays into muon pairs, $(N_{\psi (2S)}/N_{J/\psi }{)}_{\mathrm{PbPb}}/(N_{\psi (2S)}/N_{J/\psi }{)}_{pp}$, is determined as a function of PbPb collision centrality and charmonium transverse momentum $p_T$, in two kinematic intervals: $|y|<1.6$ covering $6.5<p_T<30\mathrm{GeV}/c$ and $1.6<|y|<2.4$ covering $3<p_T<30\mathrm{GeV}/c$. The centrality-integrated double ratios are $0.36\pm 0.08(\mathrm{stat})\pm 0.05(\mathrm{syst})$ in the first interval and $0.24\pm 0.22(\mathrm{stat})\pm 0.09(\mathrm{syst})$ in the second. The double ratio is lower than unity in all the measured bins, suggesting that the $\psi (2S)$ yield is more suppressed than the $J/\psi$ yield in the explored phase space.

We report a novel crossover behavior in the long-range-ordered phase of a prototypical spin-$1/2$ Heisenberg antiferromagnetic ladder compound ${(\mathrm{C}}_7{\mathrm{H}}_{10}\mathrm{N}{)}_2{\mathrm{CuBr}}_4$. The staggered order was previously evidenced from a continuous and symmetric splitting of ${}^{14}\mathrm{N}$ NMR spectral lines on lowering the temperature below $T_c\simeq 330\mathrm{mK}$, with a saturation towards $\simeq 150\mathrm{mK}$. Unexpectedly, the split lines begin to further separate away below $T^{*}\sim 100\mathrm{mK}$, while the linewidth and the line shape remain completely invariable. This crossover behavior is further corroborated by the NMR relaxation rate $T_1^{-1}$ measurements. A very strong suppression reflecting the ordering, $T_1^{-1}\sim T^{5.5}$, observed above $T^{*}$, is replaced by $T_1^{-1}\sim T$ below $T^{*}$. These original NMR features are indicative of the unconventional nature of the crossover, which may arise from a unique arrangement of the ladders into a spatially anisotropic and frustrated coupling network.

Hole transport experiments were performed on a gated double quantum dot device defined in a $p$-$\mathrm{GaAs}/\mathrm{AlGaAs}$ heterostructure with a single hole occupancy in each dot. The charging diagram of the device was mapped out using charge detection confirming that the single hole limit is reached. In that limit, a detailed study of the two-hole spin system was performed using high bias magnetotransport spectroscopy. In contrast to electron systems, the hole spin was found not to be conserved during interdot resonant tunneling. This allows one to fully map out the two-hole energy spectrum as a function of the magnitude and the direction of the external magnetic field. The heavy-hole $g$ factor was extracted and shown to be strongly anisotropic, with a value of 1.45 for a perpendicular field and close to zero for an in-plane field as required for hybridizing schemes between spin and photonic quantum platforms.

It is widely believed that one major life-threatening transition to chaotic fibrillation occurs via spiral-wave breakup that is preceded by spatiotemporal dispersion of refractoriness due to alternations in the duration of the cardiac action potential (AP). However, recent clinical and experimental evidence suggests that other characteristics of the AP may contribute to, and perhaps drive, this dangerous dynamical instability. To identify the relative roles of AP characteristics, we performed experiments in rabbit hearts under conditions to minimize AP duration dynamics which unmasked pronounced AP amplitude alternans just before the onset of fibrillation. We used a simplified ionic cell model to derive a return map and a stability condition that elucidates a novel underlying mechanism for AP alternans and spiral breakup. We found that inactivation of the sodium current is key to developing amplitude alternans and is directly connected to conduction block and initiation of arrhythmias. Simulations in 2D where AP amplitude alternation led to turbulence confirm our hypothesis.

Radiative transition probabilities ($A$ values) are computed for the Fe xvii $L$-shell lines in a Breit-Pauli configuration-interaction method with the autostructure atomic structure code. It is shown that, by carefully taking into account the fine-tuning of the relativistic coupling and $2p$-orbital relaxation, the measured $A$ values of the $M1$ and $M2$ lines and, for the first time, the low $f(3C)/f(3D)$ oscillator-strength ratio are satisfactorily reproduced by the theory. The present ratio $f(3C)/f(3D)=2.82$ compares well with the measurement of $2.61\pm 0.23$ by x-ray laser spectroscopy.

We report on a new effect caused by the electron-phonon coupling in a stoichiometric rare-earth antiferromagnetic crystal subjected to an external magnetic field, namely, the appearance of a nonzero gap in the spectrum of electronic excitations in an arbitrarily small field. The effect was registered in the low-temperature far-infrared (terahertz) reflection spectra of an easy-axis antiferromagnet ${\mathrm{PrFe}}_3{({\mathrm{BO}}_3)}_4$ in magnetic fields ${\mathbf{B}}_{\text{ext}}\parallel c$. Both paramagnetic and magnetically ordered phases (including a spin-flop one) were studied in magnetic fields up to 30 T, and two bifurcation points were observed. We show that the field behavior of the coupled modes can be successfully explained and modeled on the basis of the equation derived in the framework of the theory of coupled electron-phonon modes, with the same field-independent electron-phonon interaction constant $|W|=14.8{\mathrm{cm}}^{-1}$.

Atom interferometry tests of universality of free fall based on the differential measurement of two different atomic species provide a useful complement to those based on macroscopic masses. However, when striving for the highest possible sensitivities, gravity gradients pose a serious challenge. Indeed, the relative initial position and velocity for the two species need to be controlled with extremely high accuracy, which can be rather demanding in practice and whose verification may require rather long integration times. Furthermore, in highly sensitive configurations gravity gradients lead to a drastic loss of contrast. These difficulties can be mitigated by employing wave packets with narrower position and momentum widths, but this is ultimately limited by Heisenberg’s uncertainty principle. We present a promising scheme that overcomes these problems by compensating the effects of the gravity gradients and circumvents the fundamental limitations due to Heisenberg’s uncertainty principle. Furthermore, it relaxes the experimental requirements on initial colocation by several orders of magnitude.

The transfer of quantum information between physical systems of a different nature is a central matter in quantum technologies. Particularly challenging is the transfer between discrete and continuous degrees of freedom of various harmonic oscillator systems. Here we implement a protocol for teleporting a continuous-variable optical qubit, encoded by means of low-amplitude coherent states, onto a discrete-variable, single-rail qubit—a superposition of the vacuum and single-photon optical states—via a hybrid entangled resource. We test our protocol on a one-dimensional manifold of the input qubit space and demonstrate the mapping onto the equator of the teleported qubit’s Bloch sphere with an average fidelity of $0.83\pm 0.04$. Our work opens up the way to the wide application of quantum information processing techniques where discrete- and continuous-variable encodings are combined within the same optical circuit.

We investigate the ability of a quantum measurement device to discriminate two states or, generically, two hypotheses. In full generality, the measurement can be performed a number $n$ of times, and arbitrary preprocessing of the states and postprocessing of the obtained data are allowed. There is an intrinsic error associated with the measurement device, which we aim to quantify, that limits its discrimination power. We minimize various error probabilities (averaged or constrained) over all pairs of $n$-partite input states. These probabilities, or their exponential rates of decrease in the case of large $n$, give measures of the discrimination power of the device. For the asymptotic rate of the averaged error probability, we obtain a Chernoff-type bound, dual to the standard Chernoff bound for which the state pair is fixed and the optimization is over all measurements. The key point in the derivation is that identical copies of input states become optimal in asymptotic settings. Optimal asymptotic rates are also obtained for constrained error probabilities, dual to Stein’s lemma and Hoeffding’s bound. We further show that adaptive protocols where the state preparer gets feedback from the measurer do not improve the asymptotic rates. These rates thus quantify the ultimate discrimination power of a measurement device.