Analytical and numerical results, for the orbital and spin content carried by different quark flavors in the baryons, are given in the chiral quark model with symmetry breaking. The reduction of the quark spin, due to the spin dilution in the chiral splitting processes, is transferred into the orbital motion of quarks and antiquarks. The orbital angular momentum for each quark flavor in the pro...

Orbital angular momentum (OAM) has been widely studied in fibre and short-range communications. The implementation of millimetre waves with OAM is expected to increase the communication capacity. Most experiments demonstrate the distinction of OAM modes by receiving all of the energy in the surface vertical to the radiation axis in space. However, the reception of OAM is difficult in free space...

employs the Z2 noise with an unbiased subtraction. This reduced the error by a factor of 4 with negligible overhead. The total quark contribution to the proton spin is found to be 0.30±0.07. From this and the quark spin content we deduce the quark orbital angular momentum to be 0.17 ± 0.06 which is ∼ 34% of the proton spin. We further predict that the gluon angular momentum to be 0.20 ± 0.07, i...

The simple relationship between total angular momentum and energy and the seemingly natural separation of the angular momentum into spin and orbital components in the paraxial approximation, are investigated for a general nonparaxial form of monochromatic beam with near cylindrical symmetry.

Orbital angular momentum (OAM) of photons, as a new fundamental degree of freedom, has excited a great diversity of interest, because of a variety of emerging applications. Arbitrarily tunable OAM has gained much attention, but its creation remains still a tremendous challenge. We demonstrate the realization of well-controlled arbitrarily tunable OAM in both theory and experiment. We present th...

A spin-orbital superexchange Hamiltonian in a Mott insulator with t2g orbital degeneracy is investigated. More specifically, we focus on a spin ferromagnetic state of the model and study a collective behavior of orbital angular momentum. Orbital order in the model occurs in a nontrivial way—it is stabilized exclusively by quantum effects through the order-from-disorder mechanism. Several energe...

Christian Schulze,1 Filippus S. Roux,2 Angela Dudley,2 Ronald Rop,3 Michael Duparré,1 and Andrew Forbes2,4,* 1Institute of Applied Optics, Friedrich Schiller University, Fröbelstieg 1, 07743 Jena, Germany 2Council for Scientific and Industrial Research, P.O. Box 395, Pretoria 0001, South Africa 3Department of Physics, Egerton University, P.O. Box 536, Egerton 20115, Kenya 4School of Physics, Un...

We put forward an approach to estimate the amount of bipartite spatial entanglement of down-converted photon states correlated in orbital angular momentum and the magnitude of the transverse radial wave vectors. Both degrees of freedom are properly considered in our framework, which only requires azimuthal local linear optical transformations and mode selection analysis with two fiber detectors...

In the Poincaré gauge theory of gravity, which has been formulated on the basis of a principal fiber bundle over the space-time manifold having the covering group of the proper orthochronous Poincaré group as the structure group, we examine the tensorial properties of the dynamical energy-momentum density Tk μ and the “spin” angular momentum density Skl μ of the gravitational field. They are bo...

Chirality is exhibited by objects that cannot be rotated into their mirror images. It is far from obvious that this has anything to do with the angular momentum of light, which owes its existence to rotational symmetries. There is nevertheless a subtle connection between chirality and the angular momentum of light. We demonstrate this connection and, in particular, its significance in the conte...