The authors regret a mistake in simulations of the excitation coils. As a result, the used field strengths are much smaller than mentioned in the paper. In the paper we described that the AC field is 0.5 mT and the DC field is 50 mT at the location of the sample. However, this should be 0.2 mT AC and 3.3 mT DC. This won’t affect any of the results or conclusions described in the paper. We think it is even more promising that the method works this well at these low field strengths. The authors would like to apologise for any inconvenience caused.