1 pm de Broglie wavelength? What's pm?

[alv]

I'm reading about delayed-choice experiments http://arxiv.org/pdf/1407.2930.pdf and in this sentence "In modern interferometric experiments, the wave nature of molecules of approximately 7000 atomic mass units and 1 pm de Broglie wavelength has been demonstrated" I can't figure out or find out what the pm stands for. Please explain :)

 

[Let'sthink]

picometer(pm) means 10^-12 m