全文获取类型
收费全文 | 265篇 |
免费 | 88篇 |
国内免费 | 23篇 |
专业分类
化学 | 9篇 |
力学 | 3篇 |
综合类 | 2篇 |
数学 | 13篇 |
物理学 | 349篇 |
出版年
2023年 | 3篇 |
2022年 | 4篇 |
2021年 | 12篇 |
2020年 | 8篇 |
2019年 | 4篇 |
2018年 | 5篇 |
2017年 | 10篇 |
2016年 | 11篇 |
2015年 | 8篇 |
2014年 | 16篇 |
2013年 | 27篇 |
2012年 | 18篇 |
2011年 | 25篇 |
2010年 | 27篇 |
2009年 | 24篇 |
2008年 | 19篇 |
2007年 | 28篇 |
2006年 | 20篇 |
2005年 | 19篇 |
2004年 | 19篇 |
2003年 | 13篇 |
2002年 | 19篇 |
2001年 | 11篇 |
2000年 | 3篇 |
1999年 | 7篇 |
1998年 | 7篇 |
1997年 | 1篇 |
1996年 | 3篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1981年 | 1篇 |
排序方式: 共有376条查询结果,搜索用时 15 毫秒
1.
离子阱中热库诱导退相干的控制 总被引:1,自引:1,他引:0
王中结 《原子与分子物理学报》2006,23(4):757-761
对单个囚禁离子在热库作用下的退相干的控制问题进行了研究.本文提出的控制方法是基于消除自由哈密顿技术和脉冲重聚技术的结合.前者是利用一个经典大失谐激光场作用于囚禁离子来实现的,而后者是利用一系列的激光π脉冲来实现的.解析与数值表明,应用这种控制方法可以有效消除量子退相干且比纯粹应用脉冲重聚技术要好. 相似文献
2.
A. Hichri S. Jaziri R. Ferreira 《Physica E: Low-dimensional Systems and Nanostructures》2004,24(3-4):234-243
We demonstrate coupling and entangling of quantum states in a pair of vertically aligned self assembled quantum dots by studying the dynamics of two interacting electrons driven by external electric field. The present entanglement involves the spatial degree of freedom for the two electrons system. We show that system of two interacting electrons initially delocalized (localized each in one dot) oscillate slowly in response to electric field, since the strong Coulomb repulsion makes them behaving so. We use an explicit formula for the entanglement of formation of two qubit in terms of the concurrence of the density operator. In ideal situations, entangled quantum states would not decohere during processing and transmission of quantum information. However, real quantum systems will inevitably be influenced by surrounding environments. We discuss the degree of entanglement of this system in which we introduce the decoherence effect caused by the acoustic phonon. In this entangled states proposal, the decohering time depends on the external parameters. 相似文献
3.
Algebraic Formulation of Quantum Decoherence 总被引:1,自引:0,他引:1
An algebraic formalism for quantum decoherence in systems with continuous evolution spectrum is introduced. A certain subalgebra, dense in the characteristic algebra of the system, is defined in such a way that Riemann–Lebesgue theorem can be used to explain decoherence in a well defined final pointer basis. 相似文献
4.
5.
P. J. Salas 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2008,46(2):365-373
The decoherence effect on Grover algorithm has been studied numerically
through a noise modelled by a depolarizing channel. Two types of error are
introduced characterizing the qubit time evolution and gate application, so
the noise is directly related to the quantum network construction. The
numerical simulation concludes an exponential damping law for the successive
probability of the maxima as time increases. We have obtained an
allowed-error law for the algorithm: the error threshold for the allowed
noise behaves as εth(N) ∼1/N1.1 (N being the
size of the data set). As the power of N is almost one, we consider the
Grover algorithm as robust to a certain extent against decoherence. This law
also provides an absolute threshold: if the free evolution error is greater
than 0.043, Grover algorithm does not work for any number of qubits affected
by the present error model. The improvement in the probability of success,
in the case of two qubits has been illustrated by using a fault-tolerant
encoding of the initial state by means of the [[7,1,3]] quantum code. 相似文献
6.
L. Jacak A. Janutka P. Machnikowski A. Radosz J. Krasnyj 《International Journal of Theoretical Physics》2003,42(5):1065-1073
The effects resulting due to dressing of an exciton with phonons are analyzed as the source of unavoidable decoherence of orbital degrees of freedom in quantum dots. The dressing with longitudinal optical phonons results in energetic shift of order of a few meV even of the ground state of exciton in a state-of-the-art InAs/GaAs dot and the mediating role of longitudinal acoustical phonons is essential in this process. The characteristic time needed for dressing of the exciton with optical phonons is of a picosecond order. That time can be regarded as the lower limit for decoherence for optically driven quantum gates employing self-assembled quantum dot structures. 相似文献
7.
Sigmund EE Calder ES Thomas GW Mitrović VF Bachman HN Halperin WP Kuhns PL Reyes AP 《Journal of magnetic resonance (San Diego, Calif. : 1997)》2001,148(2):309-313
We have studied the temporal instability of a high field resistive Bitter magnet through nuclear magnetic resonance (NMR). This instability leads to transverse spin decoherence in repeated and accumulated NMR experiments as is normally performed during signal averaging. We demonstrate this effect via Hahn echo and Carr--Purcell--Meiboom--Gill (CPMG) transverse relaxation experiments in a 23-T resistive magnet. Quantitative analysis was found to be consistent with separate measurements of the magnetic field frequency fluctuation spectrum, as well as with independent NMR experiments performed in a magnetic field with a controlled instability. Finally, the CPMG sequence with short pulse delays is shown to be successful in recovering the intrinsic spin--spin relaxation even in the presence of magnetic field temporal instability. 相似文献
8.
9.
10.
We investigate the quantum-classical transition of a kicked rotor (KR) under perturbation by a second one. The influence of such a chaotic KR makes decoherence of the first one, resulting in the emergence of classical diffusion from its quantum dynamics. Such quantum-classical transition persists by decreasing the effective Planck's constant h, and at the same time, decreasing the mass of the second KR and the interaction strength proportionally. In the limit of h → 0, due to vanishing small mass and interaction, the second KR has almost no effect on the classieal dynamics of the first one. We demonstrate this via two different coupling potentials. 相似文献