4.
What recent breakthrough achievement has been announced by an international team of researchers, as described in the provided article?
A:
Successful creation of anti-hydrogen using laser cooling techniques
B:
Laser cooling of hydrogen atoms to near absolute zero temperatures
C:
Laser cooling of Positronium atoms for the first time in quantum research
D:
Demonstration of positron-electron interactions in a Bose Einstein Condensate
The answer is:
C
