While you should indeed be job searching immediately, the unemployment situation is not so cut and dried in your jurisdiction (or in most).  

1. As soon as you are not paid, you should call your unemployment office and file for unemployment to get a determination of benefits - http://www.edd.ca.gov/Unemployment/FAQ_-_Eligibility.htm. You can always file, they have processes to determine eligibility - it's not "fraud" assuming you answer all the questions honestly.  In any pay period you don't get paid for work, you should be filing - don't wait. Even if the automatic phone or web thingy says you're not eligible this will trigger a followup phone call with a person who you can explain the situation to and they can tell you if you're eligible (or if you would be if you quit). They will never do a determination of benefits if you don't apply, so apply. Worst case is they don't pay out.

2. Or you can up and quit. Specifically in CA employment law you can still be eligible after a "[voluntary quit][1]" if it was for "[good cause][1]". Only the EDD can make the determination, but not getting paid seems to me to fit the category pretty well. 


  [1]: http://www.edd.ca.gov/UIBDG/Voluntary_Quit_VQ_5.htm