Three sets of chiral doublet band structures have been identified in the ${}^{103}\mathrm{Rh}$ nucleus. The properties of the observed chiral doublet bands are in good agreement with theoretical results obtained using constrained covariant density functional theory and particle rotor model calculations. Two of them belong to an identical configuration and provide the first experimental evidence for a novel type of multiple chiral doublets, where an “excited” chiral doublet of a configuration is seen together with the “yrast” one. This observation shows that the chiral geometry in nuclei can be robust against the increase of the intrinsic excitation energy.

We study the Josephson junction mediated by the quantum spin Hall edge states and show that electron-electron interactions lead to a dissipationless fractional Josephson effect in the presence of time-reversal symmetry. Surprisingly, the periodicity is $8\pi$, corresponding to a Josephson frequency $eV/2\hslash$. We estimate the magnitude of interaction-induced many-body level splitting responsible for this effect and argue that it can be measured by using tunneling spectroscopy. For strong interactions we show that the Josephson effect is associated with the weak tunneling of charge $e/2$ quasiparticles between the superconductors. Our theory describes a fourfold ground state degeneracy that is similar to that of coupled “fractional” Majorana modes but is protected by time-reversal symmetry.

We propose a setup that is the spin analog of the charge-based quantum $RC$ circuit. We define and compute the spin capacitance and the spin resistance of the circuit for both ferromagnetic and antiferromagnetic systems. We find that the antiferromagnetic setup has universal properties, but the ferromagnetic setup does not. We discuss how to use the proposed setup as a quantum source of spin excitations, and put forward two possible experimental realizations, using either ultracold atoms in optical lattices or artificially engineered atomic-spin chains.

Inhibited passing of reactant and product molecules within the linear pores of nanoporous catalytic materials strongly reduces reactivity. The dependence of the passing propensity $P$ on pore radius $R$ is analyzed utilizing Langevin dynamics to account for solvent effects. We find that $P\sim {(R-R_c)}^{\sigma }$, where passing is sterically blocked for $R\le R_{\mathit{c}}$, with $\sigma$ below the transition state theory value. Deeper insight comes from analysis of the corresponding high-dimensional Fokker-Planck equation, which facilitates an effective small-$P$ approximation, and dimensional reduction enabling utilization of conformal mapping ideas. We analyze passing for spherical molecules and also assess the effect of rotational degrees of freedom for elongated molecules.

Nuclear spins support long lived quantum coherence due to weak coupling to the environment, but are difficult to rapidly control using nuclear magnetic resonance as a result of the small nuclear magnetic moment. We demonstrate a fast $\sim 500\mathrm{ns}$ nuclear spin phase gate on a ${}^{14}\mathrm{N}$ nuclear spin qubit intrinsic to a nitrogen-vacancy center in diamond. The phase gate is enabled by the hyperfine interaction and off-resonance driving of electron spin transitions. Repeated applications of the phase gate bang-bang decouple the nuclear spin from the environment, locking the spin state for up to $\sim 140\mu \mathrm{s}$.

We establish a relation between two hallmarks of integrable systems: the relaxation towards the generalized Gibbs ensemble (GGE) and the dissipationless charge transport. We show that the former one is possible only if the so-called Mazur bound on the charge stiffness is saturated by local conserved quantities. As an example we show how a non-GGE steady state with a current can be generated in the one-dimensional model of interacting spinless fermions with a flux quench. Moreover, an extended GGE involving the quasilocal conserved quantities can be formulated for this case.

Multiple scattering represents a challenge for numerous modern tomographic imaging techniques. In this Letter, we derive an appropriate line integral that allows for the tomographic reconstruction of angular resolved scattering distributions, even in the presence of multiple scattering. The line integral is applicable to a wide range of imaging techniques utilizing various kinds of probes. Here, we use x-ray grating interferometry to experimentally validate the framework and to demonstrate additional structural sensitivity, which exemplifies the impact of multiple scattering tomography.

Recently, it was shown that the spectrum of anomalous dimensions and other important observables in planar $\mathcal{N}=4$ supersymmetric Yang-Mills theory are encoded into a simple nonlinear Riemann-Hilbert problem: the $\mathbf{P}\mu$ system or quantum spectral curve. In this Letter, we extend this formulation to the $\mathcal{N}=6$ supersymmetric Chern-Simons theory introduced by Aharony, Bergman, Jafferis, and Maldacena. This may be an important step towards the exact determination of the interpolating function $h(\lambda )$ characterizing the integrability of this model. We also discuss a surprising relation between the quantum spectral curves for the $\mathcal{N}=4$ supersymmetric Yang-Mills theory and the $\mathcal{N}=6$ supersymmetric Chern-Simons theory considered here.

Double-spin asymmetries and absolute cross sections were measured at large Bjorken $x(0.25\le x\le 0.90)$, in both the deep-inelastic and resonance regions, by scattering longitudinally polarized electrons at beam energies of 4.7 and 5.9 GeV from a transversely and longitudinally polarized ${}^3\mathrm{He}$ target. In this dedicated experiment, the spin structure function $g_2^{{}^3\mathrm{He}}$ was determined with precision at large $x$, and the neutron twist-3 matrix element $d_2^n$ was measured at $⟨Q^2⟩$ of 3.21 and $4.32{\mathrm{GeV}}^2/c^2$, with an absolute precision of about $10^{-5}$. Our results are found to be in agreement with lattice QCD calculations and resolve the disagreement found with previous data at $⟨Q^2⟩=5{\mathrm{GeV}}^2/c^2$. Combining $d_2^n$ and a newly extracted twist-4 matrix element $f_2^n$, the average neutron color electric and magnetic forces were extracted and found to be of opposite sign and about $30\mathrm{MeV}/\mathrm{fm}$ in magnitude.

We report the first measurement of the target-normal single-spin asymmetry in deep-inelastic scattering from the inclusive reaction ${{}^3\mathrm{He}}^{\uparrow }(e,e^{\prime })X$ on a polarized ${}^3\mathrm{He}$ gas target. Assuming time-reversal invariance, this asymmetry is strictly zero in the Born approximation but can be nonzero if two-photon-exchange contributions are included. The experiment, conducted at Jefferson Lab using a 5.89 GeV electron beam, covers a range of $1.7<W<2.9\mathrm{GeV}$, $1.0<Q^2<4.0{\mathrm{GeV}}^2$ and $0.16<x<0.65$. Neutron asymmetries were extracted using the effective nucleon polarization and measured proton-to-${}^3\mathrm{He}$ cross-section ratios. The measured neutron asymmetries are negative with an average value of $(-1.09\pm 0.38)\times 10^{-2}$ for invariant mass $W>2\mathrm{GeV}$, which is nonzero at the $2.89\sigma$ level. Our measured asymmetry agrees both in sign and magnitude with a two-photon-exchange model prediction that uses input from the Sivers transverse momentum distribution obtained from semi-inclusive deep-inelastic scattering.

This Letter reports on a systematic study of $\beta$-decay half-lives of neutron-rich nuclei around doubly magic ${}^{208}\mathrm{Pb}$. The lifetimes of the 126-neutron shell isotone ${}^{204}\mathrm{Pt}$ and the neighboring ${}^{200–202}\mathrm{Ir}$, ${}^{203}\mathrm{Pt}$, ${}^{204}\mathrm{Au}$ are presented together with other 19 half-lives measured during the “stopped beam” campaign of the rare isotope investigations at GSI collaboration. The results constrain the main nuclear theories used in calculations of $r$-process nucleosynthesis. Predictions based on a statistical macroscopic description of the first-forbidden $\beta$ strength reveal significant deviations for most of the nuclei with $N<126$. In contrast, theories including a fully microscopic treatment of allowed and first-forbidden transitions reproduce more satisfactorily the trend in the measured half-lives for the nuclei in this region, where the r-process pathway passes through during $\beta$ decay back to stability.

Cavity optomechanical phenomena, such as cooling, amplification, or optomechanically induced transparency, emerge due to a strong imbalance in the dissipation rates of the parametrically coupled electromagnetic and mechanical resonators. Here we analyze the reversed dissipation regime where the mechanical energy relaxation rate exceeds the energy decay rate of the electromagnetic cavity. We demonstrate that this regime allows for mechanically induced amplification (or cooling) of the electromagnetic mode. Gain, bandwidth, and added noise of this electromagnetic amplifier are derived and compared to amplification in the normal dissipation regime. In addition, we analyze the parametric instability, i.e., optomechanical Brillouin lasing, and contrast it to conventional optomechanical phonon lasing. Finally, we propose an experimental scheme that realizes the reversed dissipation regime using parametric coupling and optomechanical cooling with a second electromagnetic mode enabling quantum-limited amplification. Recent advances in high-$Q$ superconducting microwave resonators make the reversed dissipation regime experimentally realizable.

Perfectly crystalline solids are excellent heat conductors. Prominent counterexamples are intermetallic clathrates, guest-host systems with a high potential for thermoelectric applications due to their ultralow thermal conductivities. Our combined experimental and theoretical investigation of the lattice dynamics of a particularly simple binary representative, ${\mathrm{Ba}}_8{\mathrm{Si}}_{46}$, identifies the mechanism responsible for the reduction of lattice thermal conductivity intrinsic to the perfect crystal structure. Above a critical wave vector, the purely harmonic guest-host interaction leads to a drastic transfer of spectral weight to the guest atoms, corresponding to a localization of the propagative phonons.

The binary phase diagram of ${\mathrm{N}}_2\text{−}\mathrm{Ne}$ mixtures has been measured at 296 K by visual observation and Raman spectroscopy. The topology of the phase diagram points to the existence of the stoichiometric compound $({\mathrm{N}}_2{)}_6{\mathrm{Ne}}_7$. Its structure has been solved by single-crystal synchrotron x-ray diffraction. The ${\mathrm{N}}_2$ molecules form a guest lattice that hosts the Ne atoms. This insertion compound can be viewed as a clathrate with the centers of the ${\mathrm{N}}_2$ molecules forming distorted dodecahedron cages, each enclosing 14 Ne atoms. Remarkably, the $({\mathrm{N}}_2{)}_6{\mathrm{Ne}}_7$ compound is somehow the first clathrate organized by the quadrupolar interaction.

Using femtosecond time-resolved x-ray diffraction, we directly monitor the coherent lattice dynamics through an ultrafast charge-density-wave-to-metal transition in the prototypical Peierls system ${\mathrm{K}}_{0.3}{\mathrm{MoO}}_3$ over a wide range of relevant excitation fluences. While in the low fluence regime we directly follow the structural dynamics associated with the collective amplitude mode; for fluences above the melting threshold of the electronic density modulation we observe a transient recovery of the periodic lattice distortion. We can describe these structural dynamics as a motion along the coordinate of the Peierls distortion triggered by the prompt collapse of electronic order after photoexcitation. The results indicate that the dynamics of a structural symmetry-breaking transition are determined by a high-symmetry excited state potential energy surface distinct from that of the initial low-temperature state.

Weyl semimetals are paradigmatic topological gapless phases in three dimensions. We here address the effect of disorder on charge transport in Weyl semimetals. For a single Weyl node with energy at the degeneracy point and without interactions, theory predicts the existence of a critical disorder strength beyond which the density of states takes on a nonzero value. Predictions for the conductivity are divergent, however. In this work, we present a numerical study of transport properties for a disordered Weyl cone at zero energy. For weak disorder, our results are consistent with a renormalization group flow towards an attractive pseudoballistic fixed point with zero conductivity and a scale-independent conductance; for stronger disorder, diffusive behavior is reached. We identify the Fano factor as a signature that discriminates between these two regimes.