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101.
Macroscopic resonant tunneling in an rf-SQUID flux qubit under a single-cycle sinusoidal driving 下载免费PDF全文
We experimentally demonstrate the observation of macroscopic resonant tunneling(MRT) phenomenon of the macroscopic distinct flux states in a radio frequency superconducting quantum interference device(rf-SQUID) under a singlecycle sinusoidal driving.The population of the qubit exhibits interference patterns corresponding to resonant tunneling peaks between states in the adjacent potential wells.The dynamics of the qubit depends significantly on the amplitude,frequency,and initial phase of the driving signal.We do the numerical simulations considering the intra-well and interwell relaxation mechanism,which agree well with the experimental results.This approach provides an effective way to manipulate the qubit population by adjusting the parameters of the external driving field. 相似文献
102.
从量子力学诞生以来,关于宏观物体的运动是否遵循量子力学的辩论就一直没有停止过.上世纪八十年代初期以来,一系列在约瑟夫森结和超导最子干涉器件(SQUID)中观测到的实验结果,包括相位和磁通的宏观量子隧穿,能级量子化,宏观共振隧穿,和在微波驱动下的相干动力学过程对认为宏观物体的运动在满足一定条件下同样遵循量子力学规律的观点提供了强有力的实验证据.在众多已观察到的宏观量子现象中,宏观共振隧穿结合了能级分立和隧穿这两个最具特征的量子现象.由于宏观共振隧穿的观测无需使用高频电磁波激发,这就避免了实验结果也可以用经典物理解释的可能,所以在一个系统中观测到宏观共振隧穿可以说是展示该系统的量子属性的最有力证据.本文讨论近年来从理论和实验两方面理解耗散和磁通噪声对类似SQUID的双势阱系统宏观共振隧穿率和谱线形状的影响.评述宏观共振隧穿谱的测量在探寻、理解、克服超导磁通量子比特中的退相干机制并最终实现规模化量子计算方面的应用. 相似文献
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105.
Otto Seeberg 《Journal of statistical physics》1972,4(2-3):83-102
The state of a gas is characterized by occupation numbers of cells in-space. The mean values and fluctuations of these numbers are studied with the help of a master equation. The results are discussed within the framework of the theory of random forces. An equation of motion of the time-correlation function (TCF) is derived and it is shown that the temporal development of the TCF can be described by a linearized Boltzmann equation.The support of the Deutsche Forschungs-Gemeinschaft (DFG) is gratefully acknowledged. 相似文献
106.
O. M. Ostrikov 《Journal of Applied Mechanics and Technical Physics》2008,49(5):872-876
The effect of changes in density of twinning dislocations on one boundary of the wedge twin on the configuration of the stress
fields generated by the latter is considered on the basis of a macroscopic dislocation model. Specific features of violation
of symmetry of the stress-field distribution near the wedge twin with different shapes of the boundaries are demonstrated
for the case of different densities of twinning dislocations on the twin boundaries.
__________
Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 49, No. 5, pp. 199–204, September–October, 2008. 相似文献
107.
A new micromechanics constitutive model for pure dilatant transformation plasticity of structure ceramics is proposed in this
paper. Based on the thermodynamics, micromechanics and microscalet→m transformation mechanism analysis of the TZP and PSZ ZrO2-containing ceramics, an analytic expressions of the Helmholtz and complementary free energy of the constitutive element for
the case of pure dilatant transformation is derived for the first time in a self-consistent manner. By the analysis of energy
dissipation in the forward and reverse transformations, the micromechanics constitutive law is derived in the framework of
Hill-Rice's internal variable constitutive theory.
The project is supported by the National Natural Science Foundation of China. 相似文献
108.
Herein macromolecular recognition by cyclodextrins (CDs) is summarized. Recognition of macromolecules by CDs is classified as main‐chain recognition or side‐chain recognition. We found that CDs form inclusion complexes with various polymers with high selectivity. Polyrotaxanes in which many CDs are entrapped in a polymer chain were prepared. Tubular polymers were prepared from the polyrotaxanes. CDs were found to recognize side‐chains of polymers selectively. CD host polymers were found to form gels with guest polymers in water. These gels showed self‐healing properties. When azobenzene was used as a guest, the gel showed sol‐gel transition by photoirradiation. When ferrocene was used, redox‐responsive gels were obtained. Macroscopic self‐assembly through molecular recognition has been discovered. Photoswitchable gel association and dissociation have been observed. 相似文献
109.
110.
宋代灾荒颇多,社会中富民这一阶层在灾荒时期也发挥了不小的作用。富民参加灾荒救济活动分自愿参与和政府强制参与两种形式,但不论是何种形式,富民的救济活动应该在政府的宏观调控下发挥功效,过分的夸大富民的作用以及一味的剥削其财富,都会使社会矛盾激化,最终使政府处于艰难的境地。 相似文献