iprobe is used for stb analysis.I would suggest that you don't use it and at the setup form of pz analysis just declare the output(s) of your circuit.
Also check the options tab of the analysis,there is a choise there that let's you define the maximum frequency that the simulator will take into account during the
analysis run.Maybe you have specified a very low freq. there and that's why you can't see the pole you are expecting.
The pz will analyze your circuit and will illustrate the result of the applied method of compensation.
Spectre can't be just declared the outputs, and it enforce me to declare input voltage or current source.
Then I replace the iprobe with a large inductor in order to break the feedback loop at ac analysis.
But the pz results still can't match Bode plot.
When output voltage is declared, Positive Output Node: Vout, Negative Output Node: ground,
there is no pole and zero in the result.
Or when output probe is set as the large inductor, also the pole and zero doesn't match Bode plot.
In the Bode plot, the dominant pole is at -2e-1 Hz
But at pz analysis, there're 2 conjugate poles at -3e-11 +/- j3e-10 Hz, and 2 zeros at -1e-27 Hz, -2e7 Hz
Is any thing wrong in my pz analysis setting?