Using the tight-binding approximation and the transfer matrix method, this paper studies the electronic transport properties through a periodic array of quantum-dot (QD) rings threaded by a magnetic flux. It demonst...Using the tight-binding approximation and the transfer matrix method, this paper studies the electronic transport properties through a periodic array of quantum-dot (QD) rings threaded by a magnetic flux. It demonstrates that the even^odd parity of the QD number in a single ring and the number of the QD rings in the array play a crucial role in the electron transmission. For a single QD ring, the resonance and antiresonance transmission depend not only on the applied magnetic flux but also on the difference between the number of QDs on the two arms of the ring. For an array of QD rings, the transmission properties are related not only to the even-odd parity of the number No of QDs in the single ring but also to the even-odd parity of the ring number N in the array. When the incident electron energy is aligned with the site energy, for the array of N rings with No = odd the antiresonance transmission cannot occur but the resonance transmission may occur and the transmission spectrum has N resonance peaks (N - 1 resonance peaks) in a period for N = odd (for N = even). For the array of N rings with No = even the transmission properties depend on the flux threading the ring and the QD number on one arm of the ring. These results may be helpful in designing QD devices.展开更多
A wavelength-tunable, efficient, and high-average power single diode-pumped continuons wave (CW) Yb:SSO laser is reported. A maximum output power of 8.8 W at 1 062.6 nm is obtained using the absorbed pump power of ...A wavelength-tunable, efficient, and high-average power single diode-pumped continuons wave (CW) Yb:SSO laser is reported. A maximum output power of 8.8 W at 1 062.6 nm is obtained using the absorbed pump power of 11.7 W, which corresponds to a slope efficiency of 85.5% and an optical-to-optical conversion efficiency of 48.9%. The wavelength tuning of the Yb:SSO laser pumped by the 976-nm LD is also investigated. The results show the tuning range from 1 002.30 to 1068.47 nm, which corresponds to a tunability range of 66.17 nm.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 10774094 and 10775091)National Fundamental Fund of Personnel Training (Grant No. J0730317)Natural Science Foundation of Shanxi Province of China (GrantNo. 2009011001-1)
文摘Using the tight-binding approximation and the transfer matrix method, this paper studies the electronic transport properties through a periodic array of quantum-dot (QD) rings threaded by a magnetic flux. It demonstrates that the even^odd parity of the QD number in a single ring and the number of the QD rings in the array play a crucial role in the electron transmission. For a single QD ring, the resonance and antiresonance transmission depend not only on the applied magnetic flux but also on the difference between the number of QDs on the two arms of the ring. For an array of QD rings, the transmission properties are related not only to the even-odd parity of the number No of QDs in the single ring but also to the even-odd parity of the ring number N in the array. When the incident electron energy is aligned with the site energy, for the array of N rings with No = odd the antiresonance transmission cannot occur but the resonance transmission may occur and the transmission spectrum has N resonance peaks (N - 1 resonance peaks) in a period for N = odd (for N = even). For the array of N rings with No = even the transmission properties depend on the flux threading the ring and the QD number on one arm of the ring. These results may be helpful in designing QD devices.
基金supported by the National Natural Science Foundation of China(No.60921004)the National Basic Research Program of China(No.2011CB808101)
文摘A wavelength-tunable, efficient, and high-average power single diode-pumped continuons wave (CW) Yb:SSO laser is reported. A maximum output power of 8.8 W at 1 062.6 nm is obtained using the absorbed pump power of 11.7 W, which corresponds to a slope efficiency of 85.5% and an optical-to-optical conversion efficiency of 48.9%. The wavelength tuning of the Yb:SSO laser pumped by the 976-nm LD is also investigated. The results show the tuning range from 1 002.30 to 1068.47 nm, which corresponds to a tunability range of 66.17 nm.