In this experiment, performed the by the Low Temperature Experimental Group in the physics department of Brown University (PI Humphrey Maris, Hazard Professor of Physics), the motion of individual electrons is captured on video camera. Due to the special properties of liquid helium, when electrons are inserted into the liquid, they force open a cavity of approximately 19 Angstroms, known as the electron bubble. If a negative pressure of around 2 barr is applied, the bubble becomes unstable and "explodes" to a size large enough to be seen by a home video camera. This negative pressure is achieved using an ultrasonic transducer. A HeNe laser is synced to the transducer, and the result is captured on film and shown here.
Most of the electrons follow a straight path along the heat flow in the cell. However, some follow curving, snake-like paths. We have shown that they are trapped on quantum vortices.
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