Resonant electric dipole-dipole interactions between cold Rydberg atoms in a magnetic field

Laser cooled Rb atoms were optically excited to 46d Rydberg states. A microwave pulse transferred a fraction of the atoms to the 47p Rydberg state. The resonant electric dipole-dipole interactions between atoms in these two states were probed using the linewidth of the two-photon microwave transition 46d-47d. The presence of a weak magnetic field (approximately 0.5 G) reduced the observed line broadening, indicating that the interaction is suppressed by the field. The field removes some of the energy degeneracies responsible for the resonant interaction, and this is the basis for a quantitative model of the resulting suppression. A technique for the calibration of magnetic field strengths using the 34s-34p one-photon transition is also presented.Comment: Accepted for publication in Physical Review

Determination of the Rb ng-series quantum defect by electric-field-induced resonant energy transfer between cold Rydberg atoms

Resonant energy transfer between cold Rydberg atoms was used to determine Rydberg atom energy levels, at precisions approaching those obtainable in microwave spectroscopy. Laser cooled Rb atoms from a magneto-optical trap were optically excited to 32d Rydberg states. The two-atom process 32d(j=5/2) + 32d(j=5/2) -> 34p(j=3/2) + 30g is resonant at an electric field of approximately 0.3 V/cm. This process is driven by the electric dipole-dipole interaction, which is allowed due to the partial f character that the g state acquires in an electric field. The experimentally observed resonant field, together with the Stark map calculation is used to make a determination of the Rb ng-series quantum defect: delta_g (n=30) = 0.00405(6)

Spectroscopic observation of resonant electric dipole-dipole interactions between cold Rydberg atoms

Resonant electric dipole-dipole interactions between cold Rydberg atoms were observed using microwave spectroscopy. Laser-cooled Rb atoms in a magneto-optical trap were optically excited to 45d Rydberg states using a pulsed laser. A microwave pulse transferred a fraction of these Rydberg atoms to the 46p state. A second microwave pulse then drove atoms in the 45d state to the 46d state, and was used as a probe of interatomic interactions. The spectral width of this two-photon probe transition was found to depend on the presence of the 46p atoms, and is due to the resonant electric dipole-dipole interaction between 45d and 46p Rydberg atoms.Comment: 5 pages, 3 figures. Accepted for publication in Phys. Rev. Lett. Titles and e-print numbers of references added to this versio

Evaluation of Impact of Smart Schools on Academic Achievement of High School's Student in Lorestan Province

Abstract: In developed countries, there is a developing global movement for change in the educational structure, the transformation of societies from traditional societies to knowledge-based societies result in the emergence of the use of the new communication environment. Smart school can be considered a learning atmosphere that will make it possible to realize a knowledge-based society. This study examined the impact of smart schools on academic achievement in Lorestan province. The population of this study is comprised of all high school students in Lorestan. The study sample consisted of 208 students that 99 people of them were smart schools' students and 109 people of them were traditional school students. The research tool in the study was the questionnaire which specified the social class with the validity and reliability of 89%. The research method of data collection for the study was causal - or post-hoc comparisons application of research. Smart school and traditional schools students’ GPA, were compared by using T-test in two different major: mathematic and scientific. Results showed that the average GPA of students in smart schools significantly differed from the traditional school grade point average and smart schools had a positive impact on students ' grade point average

Haplotype association of ovine leptin gene on breeding value of body measurements in Makooei sheep breed

The research was undertaken to find association of genetic variation in the exon 3 of the leptin gene and breeding value of body weight traits in Makooei sheep breed using single strand conformation polymorphism (SSCP). The PCR product was obtained to encompass exon 3 of leptin gene corresponding to ovine leptin gene. The PCR fragments were subjected to electrophoresis to reveal the SSCP patterns. Among the total of 130 sheep, five SSCP patterns (haplotypes) were identified for amplified fragment. The frequencies of SSCP patterns of polymorphic fragment were 0.09, 0.17, 0.37, 0.14 and 0.23.The relation between the different haplotypes and body measurements including body length (BL), heart girth (HG), height at withers (HW), height at back (HB), rump length (RL) and scrotal circumference (SC) were ascertained in all of the analyzed animals. According to our results, there is significant association between the different haplotypes of this fragment with additive estimated breeding value for the HG and RL traits. These results confirmed the potential usefulness of leptin gene in marker-assisted selection programs for sheep breeding in Makooei sheep breed

Quality enhancement in refrigerated tiger tooth croaker (Otolithes ruber) fillets using chitosan coating containing green tea extract

The effects of chitosan (2%) coating combined with green tea extract (GTE) (1%) on the quality of tiger-tooth croaker (Otolithes ruber) fillets including chemical, microbiological, texture, color and sensory properties during 16 days of refrigerated storage was investigated. The color changes were significantly retared, and the texture parameteres and sensory scores were significantly improved in tiger- tooth croaker coated by chitosan, GTE and chitosan combined with GTE, compared with the control. The coincidental lowered rate of increase total volatile base (TVB) content, thiobarbitoric acid (TBA), peroxide value (POV) and free fatty acids (FFA) were obtained in tiger-tooth croaker coated chitosan+GTE. Chitosan in combination with GTE had higher inhibition on microbial growth and yielded the tigertooth croaker with higher likeness, compared with the other treatments. Therefore, fish coated with chitosan+GTE had the lowest losses in quality during refrigerated storage

Observation of Rydberg blockade between two atoms

We demonstrate experimentally that a single Rb atom excited to the $79d_{5/2}$ level blocks the subsequent excitation of a second atom located more than $10 \mu\rm m$ away. The observed probability of double excitation of $\sim 30$ is consistent with a theoretical model based on calculations of the long range dipole-dipole interaction between atoms.Comment: 4 figure