We introduce new teleportation protocols which are generalizations of the original teleportation protocols that use the Pauli group and the port-based teleportation protocols, introduced by Hiroshima and Ishizaka, that use the symmetric permutation group. We derive sufficient conditions for a set of operations, which in general need not form a group, to give rise to a teleportation protocol and provide examples of such schemes. This generalization leads to protocols with novel properties and is needed to push forward new schemes of computation based on them. Port-based teleportation protocols and our generalizations use a large resource state consisting of $N$ singlets to teleport only a single qubit state reliably. We provide two distinct protocols which recycle the resource state to teleport multiple states with error linearly increasing with their number. The first protocol consists of sequentially teleporting qubit states, and the second teleports them in a bulk.

We solve for the first time, the Faddeev equations for the bound state problem of the coupled $\Lambda \Lambda N-\Xi NN$ system to study whether or not a hypertriton with strangeness $-2$ may exist. We make use of the interactions obtained from a chiral quark model describing the low-energy observables of the two-baryon systems with strangeness 0, $-1$, and $-2$ and three-baryon systems with strangeness 0 and $-1$. The $\Lambda \Lambda N$ system alone is unbound. However, when the full coupling to $\Xi NN$ is considered, the strangeness $-2$ three-baryon system with quantum numbers $(I,J^P)=(\frac{1}{2},\frac{1}{2}\genfrac{}{}{0ex}{}{{+}^{}}{})$ becomes bound, with a binding energy of about 0.5 MeV. This result is compatible with the nonexistence of a stable ${}_{\Lambda }{}^3\mathrm{H}$ with isospin one.

We investigate the nonlinear emission dynamics of quantum dots coupled to photonic crystal cavities in the Purcell regime using luminescence intensity autocorrelation. Two laser pulses with a controlled time delay sequentially excite the coupled system inducing emission that depends on the delay and laser power. We find distinct contrasts between exciton and biexciton emission as a function of time delay which originate from different nonlinearities. A quantum optical simulation is also performed that accounts for the interaction between the laser pulses, exciton, and cavity mode.

We describe the formation of highly degenerate, Landau-level-like amplified states in a strained photonic honeycomb lattice in which amplification breaks the sublattice symmetry. As a consequence of the parity anomaly, the zeroth Landau level is localized on a single sublattice and possesses an enhanced or reduced amplification rate. The selection of the sublattice depends on the strain orientation but is independent of the valley. The spectral properties of the higher Landau levels are constrained by a generalized time-reversal symmetry. In the setting of two-dimensional photonic crystal lasers, the anomaly affects the mode selection and lasing threshold while in three-dimensional photonic lattices it can be probed via the beam dynamics.

The dynamics and stability of brittle cracks are not yet fully understood. Here we use the Willis-Movchan 3D linear perturbation formalism [J. Mech. Phys. Solids 45, 591 (1997)] to study the out-of-plane stability of planar crack fronts in the framework of linear elastic fracture mechanics. We discuss a minimal scenario in which linearly unstable crack front corrugations might emerge above a critical front propagation speed. We calculate this speed as a function of Poisson’s ratio and show that corrugations propagate along the crack front at nearly the Rayleigh wave speed. Finally, we hypothesize about a possible relation between such corrugations and the long-standing problem of crack branching.

We consider the intermittent behavior of superfluid turbulence in ${}^4\mathrm{He}$. Because of the similarity in the nonlinear structure of the two-fluid model of superfluidity and the Euler and Navier-Stokes equations, one expects the scaling exponents of the structure functions to be the same as in classical turbulence for temperatures close to the superfluid transition $T_{\lambda }$ and also for $T\ll T_{\lambda }$. This is not the case when the densities of normal and superfluid components are comparable to each other and mutual friction becomes important. Using shell model simulations, we propose that in this situation there exists a range of scales in which the effective exponents indicate stronger intermittency. We offer a bridge relation between these effective and the classical scaling exponents. Since this effect occurs at accessible temperatures and Reynolds numbers, we propose that experiments should be conducted to further assess the validity and implications of this prediction.

By means of first principles calculations, we compute the effective electron-phonon coupling constant $G_0$ governing the electron cooling in photoexcited bismuth. $G_0$ strongly increases as a function of electron temperature, which can be traced back to the semimetallic nature of bismuth. We also use a thermodynamical model to compute the time evolution of both electron and lattice temperatures following laser excitation. Thereby, we simulate the time evolution of (1 $-1$ 0), ($-2$ 1 1) and (2 $-2$ 0) Bragg peak intensities measured by Sciaini et al. [Nature (London) 458, 56 (2009)] in femtosecond electron diffraction experiments. The effect of the electron temperature on the Debye-Waller factors through the softening of all optical modes across the whole Brillouin zone turns out to be crucial to reproduce the time evolution of these Bragg peak intensities.

We study the quantum diffusive transport of multivalley massive Dirac cones, where time-reversal symmetry requires opposite spin orientations in inequivalent valleys. We show that the intervalley scattering and intravalley scattering can be distinguished from the quantum conductivity that corrects the semiclassical Drude conductivity, due to their distinct symmetries and localization trends. In immediate practice, it allows transport measurements to estimate the intervalley scattering rate in hole-doped monolayers of group-VI transition metal dichalcogenides (e.g., molybdenum dichalcogenides and tungsten dichalcogenides), an ideal class of materials for valleytronics applications. The results can be generalized to a large class of multivalley massive Dirac systems with spin-valley coupling and time-reversal symmetry.

The spin glass state in the spinel ${\mathrm{ZnCr}}_{2(1-x)}{\mathrm{Ga}}_{2x}{\mathrm{O}}_4$ is studied with magnetization and specific heat for $x<0.05$. The freezing temperature is independent of disorder, despite a two-level-like density of states that varies linearly with $x$. This relationship implies the energy scale for freezing is independent of disorder, in contrast to mean field theories of spin glass. We suggest that the degrees of freedom are shielded spin vacancies, quasispins, which interact via an emergent long-range force mediated by the frustrated spin background.

We experimentally demonstrate a simple and robust protocol for the detection of weak radio-frequency magnetic fields using a single electron spin in diamond. Our method relies on spin locking, where the Rabi frequency of the spin is adjusted to match the MHz signal frequency. In a proof-of-principle experiment we detect a 7.5 MHz magnetic probe field of $\sim 40\mathrm{nT}$ amplitude with $<10\mathrm{kHz}$ spectral resolution. Rotating-frame magnetometry may provide a direct and sensitive route to high-resolution spectroscopy of nanoscale nuclear spin signals.

We use a first-principles rational-design approach to identify a previously unrecognized class of antiferroelectric materials in the $Pnma$ MgSrSi structure type. The MgSrSi structure type can be described in terms of antipolar distortions of the nonpolar $P{6}_3/mmc$ ZrBeSi structure type, and we find many members of this structure type are close in energy to the related polar $P{6}_{3}mc$ LiGaGe structure type, which includes many members we predict to be ferroelectric. We highlight known $ABC$ combinations in which this energy difference is comparable to the antiferroelectric-ferroelectric switching barrier of ${\mathrm{PbZrO}}_3$. We calculate structural parameters and relative energies for all three structure types, both for reported and as-yet hypothetical representatives of this class. Our results provide guidance for the experimental realization and further investigation of high-performance materials suitable for practical applications.

Leaf sizes in angiosperm trees vary by more than 3 orders of magnitude, from a few mm to over 1 m. This large morphological freedom is, however, only expressed in small trees, and the observed leaf size range declines with tree height, forming well-defined upper and lower boundaries. The vascular system of tall trees that distributes the products of photosynthesis connects distal parts of the plant and forms one of the largest known continuous microfluidic distribution networks. In biological systems, intrinsic properties of vascular systems are known to constrain the morphological freedom of the organism. We show that the limits to leaf size can be understood by physical constraints imposed by intrinsic properties of the carbohydrate transport network. The lower boundary is set by a minimum energy flux, and the upper boundary is set by a diminishing gain in transport efficiency.

It is shown how it is possible to reconstruct the initial state of a one-dimensional system by sequentially measuring two conjugate variables. The procedure relies on the quasicharacteristic function, the Fourier transform of the Wigner quasiprobability. The proper characteristic function obtained by Fourier transforming the experimentally accessible joint probability of observing “position” then “momentum” (or vice versa) can be expressed as a product of the quasicharacteristic function of the two detectors and that unknown of the quantum system. This allows state reconstruction through the sequence (1) data collection, (2) Fourier transform, (3) algebraic operation, and (4) inverse Fourier transform. The strength of the measurement should be intermediate for the procedure to work.

We introduce a method that can orthogonalize any pure continuous variable quantum state, i.e., generate a state $|{\psi }_{\perp }⟩$ from $|\psi ⟩$ where $⟨\psi |{\psi }_{\perp }⟩=0$, which does not require significant a priori knowledge of the input state. We illustrate how to achieve orthogonalization using the Jaynes-Cummings or beamsplitter interaction, which permits realization in a number of physical systems. Furthermore, we demonstrate how to orthogonalize the motional state of a mechanical oscillator in a cavity optomechanics context by developing a set of coherent phonon level operations. As the mechanical oscillator is a stationary system, such operations can be performed at multiple times providing considerable versatility for quantum state engineering applications. Utilizing this, we additionally introduce a method how to transform any known pure state into any desired target state.

We present a measurement of the time-integrated flavor-specific semileptonic charge asymmetry in the decays of $B_s^0$ mesons that have undergone flavor mixing, $a_{\mathrm{sl}}^s$, using $B_s^0({\overline{B}}_s^0)\to D_s^{\mp }{\mu }^{\pm }X$ decays, with $D_s^{\mp }\to \varphi {\pi }^{\mp }$ and $\varphi \to K^{+}{K}^{-}$, using $10.4{\mathrm{fb}}^{-1}$ of proton-antiproton collisions collected by the D0 detector during Run II at the Fermilab Tevatron Collider. A fit to the difference between the time-integrated $D_s^{-}$ and $D_s^{+}$ mass distributions of the $B_s^0$ and ${\overline{B}}_s^0$ candidates yields the flavor-specific asymmetry $a_{\mathrm{sl}}^s=[-1.12\pm 0.74(\mathrm{stat})\pm 0.17(\mathrm{syst})]\%$, which is the most precise measurement and in agreement with the standard model prediction.

Results of a search for new phenomena in events with an energetic photon and large missing transverse momentum in proton-proton collisions at $\sqrt{s}=7\mathrm{TeV}$ are reported. Data collected by the ATLAS experiment at the LHC corresponding to an integrated luminosity of $4.6{\mathrm{fb}}^{-1}$ are used. Good agreement is observed between the data and the standard model predictions. The results are translated into exclusion limits on models with large extra spatial dimensions and on pair production of weakly interacting dark matter candidates.

The MuCap experiment at the Paul Scherrer Institute has measured the rate ${\Lambda }_S$ of muon capture from the singlet state of the muonic hydrogen atom to a precision of 1%. A muon beam was stopped in a time projection chamber filled with 10-bar, ultrapure hydrogen gas. Cylindrical wire chambers and a segmented scintillator barrel detected electrons from muon decay. ${\Lambda }_S$ is determined from the difference between the ${\mu }^{-}$ disappearance rate in hydrogen and the free muon decay rate. The result is based on the analysis of $1.2\times {10}^{10}$ ${\mu }^{-}$ decays, from which we extract the capture rate ${\Lambda }_S=(714.9\pm {5.4}_{\mathrm{stat}}\pm {5.1}_{\mathrm{syst}}){\mathrm{s}}^{-1}$ and derive the proton’s pseudoscalar coupling $g_P(q_0^2=-0.88m_{\mu }^2)=8.06\pm 0.55$.

A vortical model for freak wave formation in water is presented. The wind action is simulated by nonuniform pressure on the free surface. The motion of the fluid is described by an exact solution of 2D hydrodynamic equations for ideal inviscid fluid in Lagrangian variables. Fluid particles rotate in circles of different radius. The model describes the appearance of a freak wave in the field of the Gerstner wave. The physical parameters of the wave and feasibility of the proposed scenario are discussed.

Compressible ideal magnetohydrodynamics is formulated in terms of the time evolution of potential vorticity and magnetic flux per unit mass using a compact Lie bracket notation. It is demonstrated that this simplifies analytic solution in at least one very important situation relevant to magnetic fusion experiments. Potentially important implications for analytic and numerical modelling of both laboratory and astrophysical plasmas are also discussed.

By means of the time-dependent density-matrix renormalization-group (TDMRG) method we are able to follow the real-time dynamics of a single impurity embedded in a one-dimensional bath of interacting bosons. We focus on the impurity breathing mode, which is found to be well described by a single oscillation frequency and a damping rate. If the impurity is very weakly coupled to the bath, a Luttinger-liquid description is valid and the impurity suffers an Abraham-Lorentz radiation-reaction friction. For a large portion of the explored parameter space, the TDMRG results fall well beyond the Luttinger-liquid paradigm.