Double resonance in the infinite-range quantum Ising model

We study quantum resonance behavior of the infinite-range kinetic Ising model at zero temperature. Numerical integration of the time-dependent Schr\"odinger equation in the presence of an external magnetic field in the $z$ direction is performed at various transverse field strengths $g$. It is revealed that two resonance peaks occur when the energy gap matches the external driving frequency at two distinct values of $g$, one below and the other above the quantum phase transition. From the similar observations already made in classical systems with phase transitions, we propose that the double resonance peaks should be a generic feature of continuous transitions, for both quantum and classical many-body systems.Comment: 4 pages, 5 figure

Superconductivity-induced Phonon Renormalization on NaFe1−x_{1-x}Cox_{x}As

We report a study of the lattice dynamics in superconducting NaFeAs (Tc = 8 K) and doped NaFe0.97Co0.03As (Tc = 20 K) using Raman light scattering. Five of the six phonon modes expected from group theory are observed. In contrast with results obtained on iso-structural and iso-electronic LiFeAs, anomalous broadening of Eg(As) and A1g(Na) modes upon cooling is observed in both samples. In addition, in the Co-doped sample, a superconductivity-induced renormalization of the frequency and linewidth of the B1g(Fe) vibration is observed. This renormalization can not be understood within a single band and simple multi-band approaches. A theoretical model that includes the effects of SDW correlations along with sign-changing s-wave pairing state and interband scattering has been developed to explain the observed behavior of the B1g(Fe) mode.Comment: 10 pages; 6 figure

Osmotic potential, photosynthetic abilities and growth characters of oil palm (Elaeis guineensis Jacq.) seedlings in responses to polyethylene glycol-induced water deficit

The aim of the present study is to investigate the biochemical, physiological and morphological responses of oil palm seedlings when exposed to polyethylene glycol (PEG)-induced water deficit. Oil palm seedlings were photo-autotrophically grown in MS media and subsequently exposed to -0.23 (control), -0.42, -0.98 or -2.15 MPa PEG-induced water deficit. Osmotic potential (Ψs) in root and leaf tissues of oil palm seedlings grown under PEG-induced water deficit was decreased leading to chlorophyll degradation. Chlorophyll a (Chla), chlorophyll b (Chlb), total chlorophyll (TC), total carotenoids (Cx+c), maximum quantum yield of photosystem II (PSII) (Fv/Fm) and photon yield of PSII (ΦPSII) in the oil palm seedlings under water deficit conditions dropped significantly in comparison to the control group, leading to a reduction in net-photosynthetic rate (Pn) and growth. A positive correlation between physiological and growth parameters, including osmotic potential, photosynthetic pigments and water oxidation in photosystem II and Pn was demonstrated. These data provide the basis for the establishment of multivariate criteria for water deficit tolerance screening in oil palm breeding programs.Key words: Chlorophyll fluorescence, net-photosynthetic rate, pigment, water oxidation, water deficit stress

Screening upland rice (Oryza sativa L. ssp. indica) genotypes for salt-tolerance using multivariate cluster analysis

Seedlings of thirteen genotypes of rice were photoautotrophically grown on MS medium and subsequently exposed to 0 (control) or 200 mM NaCl (salt stress) for 14 days. Chlorophyll a (Chla), chlorophyll b (Chlb) and total carotenoids (Cx+c), in the salt stressed leaves of all genotypes decreasedsignificantly, but the extent of the decrease varied among different genotypes. Maximum quantum yield of photosystem II (PSII) (Fv/Fm), photon yield of PSII (FPSII) and net photosynthetic rate (Pn) in saltstressed seedlings of all genotypes dropped significantly, whereas FPSII in cv. Homjan (HJ), Dokpayom (DPY), Chewmaejan 2 (CMJ2) and upland rice 1 (UR1) were alleviated. Moreover, growth parameters including shoot height, root length, fresh weight, dry weight and leaf area in salt stressed plantlets of all genotypes were significantly inhibited. The pigment degradation, photosynthetic abilities and growth inhibition in saline regimes were subjected to hierarchical cluster analysis, which lead to theclassification of Kumuangluang (KML), Khao Dawk Mali (KDML), Pokkali (POK), HJ, DPY, Chewmaejan 1 (CMJ1), CMJ2, UR1 and Chowho (CH) as salt tolerant and R258, Pathumthani 1 (PT1), IR29 and upland rice 2 (UR2) as salt sensitive

Phonon arithmetic in a trapped ion system

Single-quantum level operations are important tools to manipulate a quantum state. Annihilation or creation of single particles translates a quantum state to another by adding or subtracting a particle, depending on how many are already in the given state. The operations are probabilistic and the success rate has yet been low in their experimental realization. Here we experimentally demonstrate (near) deterministic addition and subtraction of a bosonic particle, in particular a phonon of ionic motion in a harmonic potential. We realize the operations by coupling phonons to an auxiliary two-level system and applying transitionless adiabatic passage. We show handy repetition of the operations on various initial states and demonstrate by the reconstruction of the density matrices that the operations preserve coherences. We observe the transformation of a classical state to a highly non-classical one and a Gaussian state to a non-Gaussian one by applying a sequence of operations deterministically

Entanglement versus mutual information in quantum spin chains

The quantum entanglement $E$ of a bipartite quantum Ising chain is compared with the mutual information $I$ between the two parts after a local measurement of the classical spin configuration. As the model is conformally invariant, the entanglement measured in its ground state at the critical point is known to obey a certain scaling form. Surprisingly, the mutual information of classical spin configurations is found to obey the same scaling form, although with a different prefactor. Moreover, we find that mutual information and the entanglement obey the inequality $I\leq E$ in the ground state as well as in a dynamically evolving situation. This inequality holds for general bipartite systems in a pure state and can be proven using similar techniques as for Holevo's bound.Comment: 10 pages, 3 figure

Raman Scattering Study of the Lattice Dynamics of Superconducting LiFeAs

We report an investigation of the lattice dynamical properties of LiFeAs using inelastic light scattering. Five out of the six expected phonon modes are observed. The temperature evolution of their frequencies and linewidths is in good agreement with an anharmonic-decay model. We find no evidence for substantial electron-phonon coupling, and no superconductivity-induced phonon anomalies.Comment: 5 pages, 3 figures, 1 tabl

Salt stress induced ion accumulation, ion homeostasis, membrane injury and sugar contents in salt-sensitive rice (Oryza sativa L. spp. indica) roots under isoosmotic conditions

Excess salt induced ionic and osmotic stresses that disturbed metabolism and led to reduction of plant development. Previous studies reported that sugars in stressed plants were involved in stress tolerance. However, the role of sugars in salt-stressed plants against only ionic effects is still unclear. The objective of this research was to investigate accumulation and homeostasis of ions, membrane injury, water content, growth characters and sugar contents in roots, in-response to salt stress under iso-osmotic conditions. Salt-sensitive rice, Pathumthani1 (PT1) was grown on MS culture medium for 7 days and was adjusted to salt stress under iso-osmotic conditions (-1.75 ± 0.20 MPa) by mannitol for 4 days. An increase in NaCl increased Na+ and Na+:K+ in PT1 roots leading to increased membrane injury, while the water content was decreased. Additionally, growth characters, including number, length, fresh weight and dry weight of roots, were inhibited. Sugar accumulations in PT1 roots were enhanced by increases in NaCl. The increase in Na+ was positively related to total soluble sugars, resulting in an osmotic adjustment of the membrane that maintained water availability. The accumulation of sugars in PT1 roots may be a primary salt-defense mechanism and may function as an osmotic control.Key words: Mannitol, membrane injury, oligosaccharides, sodium ion, potassium ion, sodium chloride

A case of hydrated lime (CaOH)2 toxicity in

A sudden increase in mortality was observed in a fish pond stocked with 1034 6-weeks old Clarias juveniles, after exhibiting various forms of nervous disorders such as severe irritation and erratic convulsive swimming habits. A total of 165 mortality, with mean of 20.6 ± 14.8/day were recorded within the first week of stocking. A perfect positive correlation of water level in the pond R2= 0.92, with inverse mortality R2= 0.14 and pH values R2= 0.78 within the first 8 days were recorded. Carcasses exhibited various forms of skin discoloration, petechial and ecchymotic hemorrhages were observed on the cranium, base of the fins, body sides and bloated belly. Many carcasses had eroded body mucous, manifested by various forms of grayish bands of skin lesion. Mean optimal values for nitrate (0,mg/litre), nitrite (0.1,mg/litre) and ammonia (0.1mg/litre) in the water were recorded using commercial multiple water testing kit, although declining pH value of 11 to 7.5 was observed within the period. Another set of 200 Clarias juveniles of the same batch was raised in an adjacent pond, and appeared clinically healthy. Spontaneous recovery was observed upon transfer of the whole juveniles to a new pond of fresh water, with mean pH 7.5 and treated with oxytetracycline and vitaminmineral supplements. Diagnosis of acute lime toxicity was made. Normal growth was restored but, evidence of necrotic skin discoloration was retained to adulthood in 20% of the fishes.Keywords: Clarias gariepinus juveniles, hydrated lime, toxicit