Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
CPT EIT LWI |1> p p c c |3> |2> 1 i p t p e eict c p e i p t c e ic t 2 0 0 3 CPT Suppose then Population Trapping i1t i2t (0) cos( ) 2 sin( )e 2 2 (t ) c1 (t )e 1 c2 (t )e i 3 2 c3 (t )e solving Schrodinger Equation c1 (t ) c cos( ) p sin( )e 2 2 What if we’re sneaky and choose , , i Such that c1(t)=0. Then we are trapped in the two lower states. i3t 3 CPT In fact So Dark States 0 p c c c2 2p 2 p 0 0 c 0 0 p c2 2p 3 0 c 2 2 c p p 2 2 c p 0 0 c 2 2 c p p 2 2 c p Is an eigenstate of the interaction Hamiltonian CPT Coherent Population Dark State density matrix at t=0 0 0 0 22 0 32 0 23 33 11(t ) 0 Trapped in dark state Incoherent mixture density matrix at t=0 0 0 0 22 0 0 0 0 33 11(t ) 0 Rabi Oscillations EIT |1> c p c strong weak p |3> |2> d i H , i ( ) dt 2 11 i 21 31 12 13 22 23 32 33 1 i p t p e eict c 11 21 31 12 22 32 p e i p t 2 0 13 23 33 c e ict 0 3 i p t p e eict c 11 21 31 p e i p t 2 0 12 22 32 13 23 33 c e ict 211 0 i 21 2 3 31 12 13 0 0 0 0 EIT 12 p c2 2 i e i p t Im[n] Re[n]-1 EIT quant-ph/0204173 LWI We can completely eliminate absorption, can we do better? |1> l l The idea: Pump atoms into dark state, then emission from |1> can exceed absorption from ground states. c c |3> |2> BIB Quantum Optics, Scully and Zubairy,Cambridge University press 1997 Resolving conundrums in lasing without inversion via exact solutions to simple models, Scully, Quantum Opt. 6 p 203, 1994 Slow, Ultraslow, stored, and Frozen Light, Matsko,et. al., Adv.Atm.Mol.Opt.Phys. 47, p191 2001 Electromagnetically Induced Transparency, Harris, Physics Today, July 1997, p36