Universal optimal hole-doping concentration in single-layer high-temperature cuprate superconductors

We argue that in cuprate physics there are two types, hole content per CuO$_2$ plane ($P_{pl}$) and the corresponding hole content per unit volume ($P_{3D}$), of hole-doping concentrations for addressing physical properties that are two-dimensional (2D) and three-dimensional (3D) in nature, respectively. We find that superconducting transition temperature ($T_c$) varies systematically with $P_{3D}$ as a superconducting \textquotedblleft $dome$\textquotedblright with a universal optimal hole-doping concentration $P_{3D}^{opt.}$ = 1.6 $\times$ 10$^{21}$ cm$^{-3}$ for single-layer high temperature superconductors. We suggest that $P_{3D}^{opt.}$ determines the upper bound of the electronic energy of underdoped single-layer high-$T_c$ cuprates.Comment: 8 pages, 4 figures; added references ;accepted for the publication in Supercond. Sci. Technol ; Ref. 13 is revise

Far-infrared measurements of oxygen-doped polycrystalline La2CuO4.0315 superconductor under slow-cooled and fast-cooled conditions

We have studied the far-infrared (far-IR) charge dynamics of an equilibrated pure oxygen doped La2CuO4+0.0315 under slow-cooled and fast-cooled conditions. The superconducting transition temperature (Tc) for the slow-cooled and that for the fast-cooled processes were respectively found to be close to the two intrinsic Tc's: One at 30 K and the other at 15 K. Direct comparison with our previous results and other far-IR and Raman studies on single crystalline La2-xSrxCuO4, we conclude that the topology of the pristine electronic phases that are responsible for the two intrinsic Tc's is holes arranged into two-dimensional (2D) square lattices.Comment: Submitted to PR

Observation of the predicted charge collective mode of the Tc = 45 K superconducting phase of La2CuO4+{\delta}

We report the far-infrared (far-IR) observation of the Goldstone mode at ~ 72 cm-1 (~ 9 meV) predicted to exist in the superconducting phase of the transition temperature (Tc) at 45 K in the La2CuO4-based superconductors. Our observation furthers the experimental support for the two-component picture where the localized charge texture, formed at a specific planar hole density (Ppl), is tied to the HTS at Tc = 15 K, 30 K, and 45 K in a hierarchical fashion at the so-called "magic" doping level at Ppl = 1/16, 2/16, and 3/16 respectively.Comment: 3 figure

Experimental Observation of Environment-induced Sudden Death of Entanglement

We demonstrate the difference between local, single-particle dynamics and global dynamics of entangled quantum systems coupled to independent environments. Using an all-optical experimental setup, we show that, while the environment-induced decay of each system is asymptotic, quantum entanglement may suddenly disappear. This "sudden death" constitutes yet another distinct and counter-intuitive trait of entanglement.Comment: 4 pages, 4 figure

Effects of Dehydration on Freezing Characteristics and Survival in Liquid Nitrogen of Three Recalcitrant Seeds

The recalcitrant seeds rambutan( Nephelium lappaceum). durian (Durio zibethinus) and cempedak (Artocarpus inleger) have a high critical moisture content (below which ·rapid loss of viability occurs of 27.0%, 26.0% and 37.9%,respectively. The critical moisture for embroys were higher at 39.0% for rambutan, 53.9% for durian and 43.2% for Cempedak. Differential Thermal analysis of the embroyos confirmed that their threshhold moistures (below which there is no freezable water) were lower than their critical moistureS. The Threshhold moistures for rambutan, durian and cempedak embryos were approximately 30%, 32% and 33% respectively. It is suggested that unsuccessful attempts at cryopreservation of embroyos of 'recalcitrant seeds in the past maybe due to the absence of safe window between the high critical moisture content and the threshhold moisture. This results in freezing injury at the higher moistures and dehydration injury' at the lower moistures. Potential techniques to overcome this and improve cryopreservation of recalcitrant seed embryos are discussed