弱克尔介质好腔中纠缠相干态光场驱动下的贝尔态原子系统的保真度

J4 ›› 2010, Vol. 27 ›› Issue (5): 586-595.

弱克尔介质好腔中纠缠相干态光场驱动下的贝尔态原子系统的保真度

章国顺

安徽农业大学理学院, 安徽合肥 230036

收稿日期:2010-04-02 修回日期:2010-06-22 出版日期:2010-09-28 发布日期:2010-08-31
通讯作者: 章国顺(1961－),男,安徽池州人,硕士, 安徽农业大学理学院副教授,主要从事物理教学和量子光学研究。 E-mail:phyzha@ahau.edu.cn
基金资助:
国家青年自然科学基金项目(10704001),安徽省自然科学基金项目(070412060),安徽高校省级自然科学研究重点项目(kj2010123)

Fidelities of quantum states in the system of the two-mode entangled coherent field interacting with atoms in Bell states in Kerr thin medium for fine cavity

ZHANG Guoshun

School of Physics and Material Sciences, Anhui University, Hefei 230039， China

Received:2010-04-02 Revised:2010-06-22 Published:2010-09-28 Online:2010-08-31

摘要/Abstract

摘要：

运用全量子理论并结合数值计算方法，研究了含弱克尔介质好腔中的Bell态原子与纠缠相干态光场相互作用系统的保真度。结果表明，对于理想腔，若原子初始时刻处于相干保持态，腔场初态的平均光子数很小，系统保真度始终等于1,随着腔场初态的平均光子数的增加，系统保真度单调衰减，但克尔介质越弱系统保真度越接近1；若原子初始时刻处于其余Bell态之一，腔场初态的平均光子数很小，系统保真度在0～1之间作周期性振荡，随着腔场初态的平均光子数的增加，系统保真度的振荡频率增大，振幅减小。对于好腔，若原子初始时刻处于相干保持态，系统保真度呈指数单调衰减；若原子初始时刻处于其余Bell态之一，系统保真度呈指数振荡衰减，且随着腔场初态的平均光子数的增加，系统保真度的振荡频率增大，振幅减小。

关键词: 量子光学, 保真度, 全量子理论, Bell态, 弱克尔介质, 好腔

Abstract:

The fidelities of quantum states in the system of two-mode entangled coherent field interacting with two identical two-level atoms in the Bell state in Kerr thin medium are investigated by means of quantum theory and numerical method. The results indicate that for ideal cavity, the fidelity of the system always equals to one for the coherent maintenance state at original time when average photon number of two-mode entangled coherent states cavity fields are very small. When average photon number of two-mode entangled coherent states cavity fields increase, the fidelities of the system is humdrum attenuation. the fidelities of the system is nearer to one and Kerr medium more thin. The fidelities of the system surge periodically from 0 to 1 for the etceteras Bell state at original time when average photon number of two-mode entangled coherent states cavity fields are very small. When average photon number of two-mode entangled coherent states cavity fields increase, oscillatory frequency of the fidelities of the system augments and swing decrease. For fine cavity, the fidelity of the system is humdrum exponent attenuation for the coherent maintenance state at original time. The fidelities of the system are oscillatory exponent attenuation for the etceteras Bell state at original time, and when average photon number of two-mode entangled coherent states cavity fields increase, oscillatory frequency of the fidelities of the system augments and swing decrease.

Key words: quantum optics, fidelity, quantum theory, Bell states, Kerr thin medium, fine cavity

章国顺. 弱克尔介质好腔中纠缠相干态光场驱动下的贝尔态原子系统的保真度[J]. J4, 2010, 27(5): 586-595.

ZHANG Guoshun. Fidelities of quantum states in the system of the two-mode entangled coherent field interacting with atoms in Bell states in Kerr thin medium for fine cavity[J]. J4, 2010, 27(5): 586-595.

参考文献

[1] Einstein A., Podolsky B., Rosen N., et al. Can quantum-mechanical description of physical reality be considered complete [J]. Phys. Rev.,1935,47(10): 777-780.
[2] Schr dinger E. Die Gegenwartige situation in der Qunteunme chanik[J]. Naturwissenschaften, 1935, 23:807-812; 823-828; 844-849.
[3] Braunstein S L, Kimble H J. Teleportation of continuous quantum variables [J].Phy .Rev. Lett ., 1998, 80(4): 869-872
[4] Bennett C H , Brassard G, Crepean C, et al. Teleporting an unknown quantum state via dual classical and Einstein-Podolsky-Rosen channels[J]. Phys . Rev. Lett .,1993,70(13): 1895-1899
[5] Bouwmeester D , Pan J W,Mattle K, Eibl M, et al. Experimental quantum teleportation[J]. Nature, 1997, 390: 575-579
[6] Furusawa A , Sorensen J L , Braunstein S L , et al. Unconditional quantum teleportation[J]. Science, 1998, 282: 706-709
[7] Ekert A K. Quantum cryptography based on Bell’s theorem [J]. Phys . Rev. Lett ., 1991, 67(6): 661-663
[8] Ponomaredko S A ,Wolf E. Correlations in open quantum systems and associated uncertainty relations[J].Phys. Rev. A, 2001, 63: 62106
[9] Zheng S B ,Guo G C. Teleportation of super positions of macroscopic of a cavity field states[J]. Phys . Lett . A, 1997,236:180-182
[10] Sleator T., Weinfurter H. Realizable universal quantum logic gates [J]. Phys. Rev. Lett., 1995, 74:4087~4090.
[11] Gershenfield N.A., Chuang I.L. Bulk spin-resonance quantum computation [J]. Science,1997,275 :350~356.
[12] Divincenzo D.P., Bacon D., Kempe J., et al. Universal quantum computation with the exchange interaction[J]. Nature,2000,408:339~345.
[13] Imamoglu A., Awschalom D.D., Burkard G.., et al. Quantum information processing using quantum dot spins and cavity QED[J].Phys. Rev.Lett.,1999,83: 4204~4207.
[14] Cao Zhuoliang, Li Yingqun, Wang Xiancai, et al. Cavity QED technology in quantum information [J]. Chinese Journal of Quantum Electronics,2004,21(2) :244 (in Chinese)(曹卓良,李英群,汪贤才,等.量子信息中的腔QED方案简介[J].量子电子学报,2004,21(2):244~256.)
[15] Liu Chuanlong, Zheng Yizhuang. Teleportation of entangled coherent state through bipartite entangled quantum channels [J]. Acta Physica Sinica, 2006, 55(12):6222~6228.(in Chinese)(刘传龙,郑亦庄.纠缠相干态的量子隐形传态[J].物理学报, 2006, 55(12): 6222~6228.)
[16] Jozsa R. Fidelity for mixed quantum states [J]. Journal of modern optics, 1994, 41(12): 2315-2323
[17] Xie Lijun, Zhang Dengyu, Tang Shiqing. Fidelity of two-level atom’s quantum states in radiation field[J]. Chinese Journal of Quantum Electronics, 2008,25(6):719-725.(in Chinese) (谢利军,张登玉,唐世清. 辐射场中二能级原子的量子态保真度[J].量子电子学报, 2008,25(6):719-725.)
[18] Tian Yonghong, Xu Dahai,Han Libo. Fidelity of quantum information in a pair atoms of entanglement state interacting with the squeezed vacuum field [J]. chin. J. At. Mol. Phys., 2006,23(2):255~261(in Chinese).(田永红,徐大海,韩立波.纠缠态原子与压缩真空场Raman相互作用的量子信息保真度[J].原子与分子物理学报, 2006,23(2):255~261.)
[19] Liu Tangkun, Wang Jisuo, Liu Xiaojun, et al. Influence of entangled states of atomic dipole- dipole interaction on the fidelity of quantum states [J]. Acta Physica Sinica, 2000, 49(4):708~712.(in Chinese)(刘堂昆,王继锁,柳晓军.纠缠态原子偶极间相互作用对量子态保真度的影响[J].物理学报, 2000, 49(4):708~712.)
[20] Liu Sumei, Ji Yunjing, He Anzhi. Fidelity evolution of quantum state for atom and field in the two-photon process[J]. Chinese Journal of Quantum Electronics, 2009,26(2):210-217.(in Chinese).(刘素梅,纪运景,贺安之.双光子过程中原子和光场量子态保真度的演化[J].量子电子学报,2009,26(2):210-217.)
[21] Zou Yan. Fidelity of quantum states for V-type three-level atom interacting with the two-mode odd-even entangled coherent field[J]. Chinese Journal of Quantum Electronics, 2009,26(3):320-326.(in Chinese).(邹艳.V型三能级原子与双模奇偶纠缠相干光场相互作用的量子态保真度[J].量子电子学报, 2009,26(3):320-326.)
[22] Wang Zhongchun. Effect of external field on the fidelity of quantum states in the two-atom Tavis-Cummings model[J]. Acta Physica Sinica, 2006, 55(9):4624~4630.(in Chinese)(王忠纯. 外场驱动对Tavis-Cummings模型中量子态保真度的影响[J].物理学报, 2006, 55(9): 4624~4630.)