The Bloch-Siegert shift is a phenomenon observed in quantum systems under the influence of two laser fields, where the interaction of a fast-rotating laser modifies the effective resonant frequency of the system. In the rotating wave approximation (RWA), the fast rotating frequency is ignored, allowing for the identification of the actual resonant frequency, denoted as ##\omega_0##. The analysis involves transitioning between the rotating frame and the lab frame, where the shifts observed are consistent across both frames. The constant nature of the shift, represented as ##\frac{1}{4}\frac{\Omega_0^2}{\omega_0}##, despite the time-varying field, is a critical aspect of understanding this phenomenon.
PREREQUISITESStudents and researchers in quantum mechanics, physicists working with laser systems, and anyone interested in the detailed analysis of quantum resonance phenomena.
Anyone, please?Malamala said:Hello! Can someone explain to me or point me towards a basic explanation of the Bloch-Siegert shift (even the Wikipedia explanation is not clear to me)? Thank you!
So from what I understand, in RWA we ignore the fast rotating frequency and doing so we get the actual resonant frequency of the system ##\omega_0##. If we account for the fast rotating term, we basically have 2 laser lights interacting with the system, and the fast rotating one is shifting the levels that the slow rotating one is seeing, such that the measured frequency is shifted from ##\omega_0##. I am not sure I understand how they go from the rotating frame (where they get these shifts), to the lab frame (where we actually measure them). Are the shifts the same in both frames (actually there seem to be 3 frames involved in this analysis)? What confuses me even more is how can the shift be a constant in time (##\frac{1}{4}\frac{\Omega_0^2}{\omega_0}##), given that the field is time varying?A. Neumaier said:What is unclear in https://en.wikipedia.org/wiki/Bloch-Siegert_shift ?