Experimental Test of Error-Disturbance Uncertainty Relations by Weak Measurement

We experimentally test the error-disturbance uncertainty relation (EDR) in generalized, strength-variable measurement of a single photon polarization qubit, making use of weak measurement that keeps the initial signal state practically unchanged. We demonstrate that Heisenberg's EDR is violated, yet Ozawa's and Branciard's EDRs are valid throughout the range of our measurement strength.