光和超冷原子气体相互作用中的 局域场效应 董光炯 精密光谱科学与技术国家重点实验室 物理系,华东师范大学 第五届冷原子和量子信息青年物理会议, 兰州大学 2011年8月4日
光和超冷原子气体相互作用中的 局域场效应 董光炯 精密光谱科学与技术国家重点实验室 物理系，华东师范大学 第五届冷原子和量子信息青年物理会议， 兰州大学 2011年8月4日
Outline 前言 2光和相干原子分子气体相互作用中的局域场效应 3.非对称衍射和局域场效应引起的光晶格形变 4.原子在光晶格中的动力学与光晶格产生方式有关 原子晶格的超辐射 6.总结
1. 前言 2. 光和相干原子分子气体相互作用中的局域场效应 3. 非对称衍射和局域场效应引起的光晶格形变 4. 原子在光晶格中的动力学与光晶格产生方式有关 5. 原子晶格的超辐射 6.总结 Outline
2005年诺贝尔 物理学奖 量 Rewuition in production of bright, 2001 Nobel Prize! coherent atomic sources Atom optics Quantum simulation Quantum information Ultracold chemistry Quantum metrology
2005年诺贝尔 物理学奖 Atom optics Quantum simulation Quantum information Ultracold chemistry Quantum metrology
Lasers play an important role in atom optics atomic beam 经典原子光学 Diffraction Optical lens Optical mirror Interferometers /要天如 量子原子光学厘m PHYSICAL REVIEW LETTERS COHEE厘 Observation of Atom Pairs in Spontaneous Four- Wave Mixing of Two Colliding Bose-Einstein Condensate
Lasers play an important role in atom optics Diffraction Optical lens Optical mirror Interferometers 量子原子光学 经 典 原 子 光 学
Quantum Simulation ses 餐 Atoms Photoassociation oo/ Two-color an° Raman Atoms uIse Molecules Atoms
Quantum Simulation Photoassociation
The theory of interaction between light and a cold atomic gas W. Zhang and D. Walls, Phys. Rev. A 49, 3799(1994) O. Morice, Y. Castin, and J. Dalibard, Phys. Rev. A 51, 3896 (1995) J. Ruostekoski and J Javanainen, Phys. Rev. A 55, 513(1997 J. Ruostekoski and J. Javanainen. Phys. Rev. Lett. 82. 4741 (199) G. Lenz, P. Meystre, and E. Wright, Phys. Rev. Lett. 71, 3271 (1993) Y Castin and K. Mblmer, Phys. Rev. A 51, R3426(1995) K.V. Krutitsky F Burgbacher and J. Audretsch. Phys. Rev.A 59.1517(1999 K.-P. Marzlin and w. Zhang, Phys. Rev. A57, 3801(1998): 57 4761(1998): L. Dobrek, M. Gajda, M. Lewenstein, K. Seng stock, G. Birkl, and W. Ertmer, ibid. 60, R3381(1999); K.-P Marzlin, W. Zhang, and B C. Sanders, ibid. 62, 013602(2000)
The theory of interaction between light and a cold atomic gas
Interaction processes between light and a condensate Dipole potential Light induced atom-atom interaction Atom density Refraction index of the condensate Local field effect Ight propagation
Interaction processes between light and a condensate Dipole potential Light induced atom-atom interaction Refraction index of the condensate Light propagation Atom density Local field effect
PHYSICAL REVIEW A VOLUME 59. NUMBER 2 FEBRUARY 1999 Local-field approach to the interaction of an ultracold dense bose gas with a light field (2+)的-的2一+6( (+)一”-一时-△++ (A+iy/2)r 方 (2m1+1-M+(2+Gx =ej(-+12-kd的 (△+p/2)dt'+ i(△+iy/2) -i(△+iy/2) v 当时间足够长,括号中第二项可忽略 (1-e4+p/2 i(△+iy/2) 得到通常的绝热近似结果 在上述近似基础上,采用迭代计算,可以证明余下的误差 (△+iy/2 可见在大失谐的情况下,余项可抛, 绝热近似成立与否与快光/慢光无关!
( ) ( ) ( ) ( ) 2 2 /2 /2 ' /2 /2 ' 2 ? ( ) 2 2 1 1 2 1 2 0 0 ˆ ˆ ˆ ˆ ˆ ' ( ) ' ˆ 2 2 t t i i t i i t i i t i i t e V kd e dt e G e dt m + − + + − + + = − + − + − + ( ) ( ) ( ) ( ) ( ) 1 2 ( ) 2 2 1 2 /2 /2 ' /2 /2 ' 2 ? 2 2 1 1 2 0 0 ˆ ˆ 2 ˆ ˆ ˆ ˆ 2 ' ( ) ' (1 ) ' ˆ ˆ 2 ( / 2) ( / 2) t t i i t i i t i i t i i t d G G dt e V kd e dt e e dt m i i i i + + + − + + − + − + − + = − + − + − − − + − + ( ) 1 2 ( /2) 2 ˆ ˆ ˆ 2 (1 ) ( / 2) i i t G e i i + + − + − − + 在上述近似基础上，采用迭代计算，可以证明余下的误差 2 1 ~ ( / 2) + i 当时间足够长，括号中第二项可忽略， 得到通常的绝热近似结果 可见在大失谐的情况下，余项可抛， 绝热近似成立与否与快光/慢光无关！ 1 ˆ 𝜙 2
PHYSICAL REVIEW A VOLUME 59, NUMBER 2 FEBRUARY 1999 Local-field approach to the interaction of an ultracold dense bose gas with a light field +1)1-2-02-22921+G1( t=(-2+)2-1-22-h(△+的12+(2 绝数消去 h22 r)2「h P(r, t)=x(r, tEmae(r, t) xii(rn), (r. v,(rn) avi(r,t)v1(r,t) X(r,t)= dr,)1(r,n) V×V×E(r,) 8丌 1aE(r,)4丌a2p(r,t) +3a的h 4丌 a vy
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The light induced interaction between atoms have been emphasized in early research It's now widely accepeted that back influence of atomic density modification on the light propagation can be neglected in free space So far, two approaches have been applied to enhance the back influence effect One approach is to Another approach is to increase the density put an atomic gas in a cavity Sn Threee statistics and quantum tlucnntns an i Collect ve Atom kernel L ase CARLI gennum epee ef a Hose- nstein condensate chapped to a quantized light tel Cavity Opto- Mechanics with a Bose-Einstein Condensate Ferdinand Brennecke, Stephan Ritter, Tobias Donner, and Tilman Eswlinger
The light induced interaction between atoms have been emphasized in early research. It’s now widely accepeted that back influence of atomic density modification on the light propagation can be neglected in free space! 2 n So far, two approaches have been applied to enhance the back influence effect. One approach is to increase the density Another approach is to put an atomic gas in a cavity