Comment from Peter Hirschfeld

[200.202(e), 200.220] To Whom it May Concern: I am Distinguished Professor of Physics at the University of Florida, with 35 years experience in condensed matter theory. My research is involved with supererconductivity and quantum materials I am writing in my personal capacity to oppose the proposed revisions to sections 200.202(e) and 200.220 that would restrict international scientific collaboration and isolate American scientists. I have collaborated with several experimental physicists at top Chinese universities over the past 15 years or so. These labs are the leading ones in the world now in the field of quantum materials. Restriction of such collaboration can only damage the US scientific enterprise, not China's. It will constrain my access to cutting-edge results on quantum materials from Chinese labs, which will put me at a disadvantage with respect to Chinese, and also most European researchers in the field. In addition, I note that scientific connections between countries that were nominally competitors or even enemies, like the US and the Soviet Union during the cold war, are essential for achieving some kind of mutual understanding of different cultures, and serve to prevent unnecessary conflict. I am completely opposed to the types of restrictions on international collaboration being proposed.