Measurement of classical entanglement using interference fringes

Abstract Classical entanglement refers to non-separable correlations between the polarization direction and the polarization amplitude of a light field. The degree of entanglement is quantified by the Schmidt number, taking the value of unity for a separable state and two for a maximally entangled state. We propose two detection methods to determine this number based on the distinguishable patterns of interference between four light sources derived from the unknown laser beam to be detected. The second method being a modification of the first one has the interference fringes form discernable angles uniquely related to the entangled state. The maximally entangled state corresponds to fringes symmetric about the diagonal axis at either 45{\deg} or 135{\deg} direction while the separable state corresponds to fringes symmetric either about the X- or Y-axis or both simultaneously. States with Schmidt number between unity and two have fringes of symmetric angles between these two extremes. The detection methods would be beneficial to constructing transmission channels of information contained in the classically entangled states

Converting beam polarizations into entanglement and classical correlation

The nonclassicality of a macroscopic single-mode optical superposition state is potentially convertible into entanglement, when the state is mixed with the vacuum on a beam splitter. Considering light beams with polarization degree of freedom in Euclidean space as coherent product states in a bipartite Hilbert space, we propose a method to convert the polarization amplitudes into entanglement and classical correlation through generating nonclassicality in the superpositions of coherent and displaced Fock states. Equivalent Bell state emerges from the resulted superpositions and the proportion of mixed entanglement and correlation, quantified by the metric pair of negativity and Schmidt number, is determined by the two displacements along the polarization directions. We further characterize the constructed states with Wigner functions and propose an experimental method for generating these states and measuring them via homodyne tomography

Verification of {\Gamma}7_{7} symmetry assignment for the top valence band of ZnO by magneto-optical studies of the free A exciton state

The circularly-polarized and angular-resolved magneto-photoluminescence spectroscopy was carried out to study the free A exciton 1S state in wurtzite ZnO at 5 K.Comment: 4 figures, 16 pages. arXiv admin note: substantial text overlap with arXiv:0706.396

Computing Shor's algorithmic steps with classical light beams

When considered as orthogonal bases in distinct vector spaces, the unit vectors of polarization directions and the Laguerre-Gaussian modes of polarization amplitude are inseparable, constituting a so-called classical entangled light beam. We apply this classical entanglement to demonstrate theoretically the execution of Shor's factoring algorithm on a classical light beam. The demonstration comprises light-path designs for the key algorithmic steps of modular exponentiation and Fourier transform on the target integer 15. The computed multiplicative order that eventually leads to the integer factors is identified through a four-hole diffraction interference from sources obtained from the entangled beam profile. We show that the fringe patterns resulted from the interference are uniquely mapped to the sought-after order, thereby emulating the factoring process originally rooted in the quantum regime

Hierarchical chestnut-like MnCo2O4 nanoneedles grown on nickel foam as binder-free electrode for high energy density asymmetric supercapacitors

Hierarchical chestnut-like manganese cobalt oxide (MnCo2O4) nanoneedles (NNs) are successfully grown on nickel foam using a facile and cost-effective hydrothermal method. High resolution TEM image further verifies that the chestnut-like MnCo2O4 structure is assembled by numerous 1D MnCo2O4 nanoneedles, which are formed by numerous interconnected MnCo2O4 nanoparticles with grain diameter of ∼10 nm. The MnCo2O4 electrode exhibits high specific capacitance of 1535 F g−1 at 1 A g−1 and good rate capability (950 F g−1 at 10 A g−1) in a 6 M KOH electrolyte. An asymmetric supercapacitor is fabricated using MnCo2O4 NNs on Ni foam (MnCo2O4 NNs/NF) as the positive electrode and graphene/NF as the negative electrode. The device shows an operation voltage of 1.5 V and delivers a high energy density of ∼60.4 Wh kg−1 at a power density of ∼375 W kg−1. Moreover, the device exhibits an excellent cycling stability of 94.3% capacitance retention after 12000 cycles at 30 A g−1. This work demonstrates that hierarchical chestnut-like MnCo2O4 NNs could be a promising electrode for the high performance energy storage devices

An asymmetric supercapacitor with excellent cycling performance realized by hierarchical porous NiGa2O4 nanosheets

Rational design of composition and electrochemically favorable structure configuration of electrode materials are highly required to develop high-performance supercapacitors. Here, we report our findings on the design of interconnected NiGa2O4 nanosheets as advanced cathode electrodes for supercapacitors. Rietveld refinement analysis demonstrates that the incorporation of Ga in NiO leads to a larger cubic lattice parameter that promotes faster charge-transfer kinetics, enabling significantly improved electrochemical performance. The NiGa2O4 electrode delivers a specific capacitance of 1508 F g−1 at a current density of 1 A g−1 with the capacitance retention of 63.7% at 20 A g−1, together with excellent cycling stability after 10000 charge–discharge cycles (capacitance retention of 102.4%). An asymmetric supercapacitor device was assembled by using NiGa2O4 and Fe2O3 as cathode and anode electrodes, respectively. The ASC delivers a high energy density of 45.2 Wh kg−1 at a power density of 1600 W kg−1 with exceptional cycling stability (94.3% cell capacitance retention after 10000 cycles). These results suggest that NiGa2O4 can serve as a new class cathode material for advanced electrochemical energy storage applications