Ahn Y H, Choe S B, Woo J C, Kim D S, Cundiff S T, Shacklette J M, Lim Y S
School of Physics, Seoul National University, Seoul 151-742, Korea.
Phys Rev Lett. 2002 Dec 2;89(23):237403. doi: 10.1103/PhysRevLett.89.237403. Epub 2002 Nov 18.
By two-color pulse shaping, we simultaneously create virtual and real amplitudes for excitons in GaAs quantum wells, and monitor population and amplitude by pump-probe and four-wave mixing spectroscopies. Excited-state probability amplitude can be induced by the off-resonant, virtual excitations as well as by the resonant, real excitations. Population modulation in time-domain results from the interference between the virtual and real amplitudes, and the modulation depth reveals the relative contributions of these two amplitudes. The fact that virtual and real amplitudes have a phase difference of 90 degrees is demonstrated directly in time-domain.
通过双色脉冲整形，我们同时为砷化镓量子阱中的激子创建了虚拟和真实振幅，并通过泵浦探测和四波混频光谱监测粒子数和振幅。激发态概率振幅可由非共振虚拟激发以及共振真实激发诱导产生。时域中的粒子数调制源于虚拟和真实振幅之间的干涉，调制深度揭示了这两种振幅的相对贡献。虚拟和真实振幅具有90度相位差这一事实在时域中得到了直接证明。
