- #1
Malamala
- 299
- 27
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!
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 ?
The Bloch-Siegert shift is a phenomenon in nuclear magnetic resonance (NMR) spectroscopy where the resonance frequency of a spin system is shifted due to the presence of a strong radiofrequency (RF) field. This effect was first described by Felix Bloch and Rudolf Siegert in 1940.
The Bloch-Siegert shift occurs due to the interaction between the RF field and the spin system. When a strong RF field is applied, the spin system experiences a torque, causing the spins to precess around the RF field at a different frequency. This results in a shift in the resonance frequency of the spin system.
The Bloch-Siegert shift is an important phenomenon in NMR spectroscopy as it allows for the accurate measurement of the spin-lattice relaxation time (T1) and the spin-spin relaxation time (T2) of a spin system. These relaxation times provide valuable information about the structure and dynamics of molecules in a sample.
Yes, the Bloch-Siegert shift has also been observed in other spectroscopic techniques such as electron paramagnetic resonance (EPR) and nuclear quadrupole resonance (NQR). In these techniques, the shift is referred to as the Bloch-Siegert effect.
Yes, the Bloch-Siegert shift has several practical applications in fields such as chemistry, biology, and medicine. It is used in NMR-based techniques for studying molecular structures, dynamics, and interactions. It also has potential applications in medical imaging for the diagnosis and treatment of diseases.