Scientists have presented a new way to study Bose-Einstein condensates (BECs) that are the coldest objects in the Universe by canceling the damage caused by light.
New Journal of Physics
Bose-Einstein condensates (BECs):
BECs are considered as the coldest objects in the universe as they are very close to absolute zero, i.e. very near 0 K or −273.15 °C. They consist of few clusters of atoms. At such temperature, atoms behave as a single macroscopic entity by losing their individual character.
BECs are considered as the best objects to study physics due to very little “noise” or disturbance associated with them. However, these objects are also very difficult to study as they are so fragile that a single photon of light can heat and destroy them.
In the present study, scientists presented a way to study BECs by using a filter to cancel out the destruction caused by light (i.e., off-resonant light), thereby helping in measurement of BECs. The new method can also use these measurements to actively feedback to the BECs and remove some of the heating based on what has already been observed.
“It’s like trying to check if your refrigerator is still working but not wanting to let cold air out by opening the door,” said Michael Hush, from the University of Nottingham.
“The smallest amount of heat can destroy a BEC and many of even the most up-to-date imaging devices end up destroying the BEC after a single image. Experimentalists have demonstrated that a BEC can be imaged non-destructively for a limited amount of time, but our work will allow them to be imaged for much, much longer – potentially indefinitely.”
This way of measuring BECs could also be used in atom lasers to precisely determine gravity, as models in astronomy to study the emission of Hawking radiation coming from the black holes, and by military personnel to detect submarines, underground bunkers and threats, and to see through stealth technology.
For technical details, see the sources below.
Physicists find a way to study coldest objects in the Universe – IOP (http://goo.gl/Xo0wUG)
M R Hush et al. (2013). Controlling spontaneous-emission noise in measurement-based feedback cooling of a Bose–Einstein condensate New Journal of Physics DOI: 10.1088/1367-2630/15/11/113060