The unification of general relativity and quantum mechanics remains one of the great challenges in modern physics. A fundamental aspect that separates the microscopic world of ‘quantum weirdness’ from regular classical physics that we are much more intuitively familiar with is entanglement. Two quantum particles that interact with each other become entangled, such that subsequently measuring or manipulating the properties of one half of the pair will affect the other entangled partner. This experimental project aims to create entangled states where the entanglement is between atoms of different mass. Such an entangled state is created by individual collisions between pairs of metastable helium atoms from a degenerate Fermi gas (3He atoms) and a Bose-Einstein condensate (4He atoms).
We will exploit the unique capabilities of ultracold helium atoms trapped in the long lived (lifetime ~ 2 hours) metastable state (designated He*) to conduct a number of experiments testing various fundamental aspects of quantum entanglement. The novel single atom detection He* provides allows the correlations necessary that show entanglement to be directly measured.
Scientific goals of this project include using 3He* to measure anti-bunching (a manifestation of the Pauli exclusion principle), studying the suppression of bosonic bunching due to fermions , investigating gravitational decoherence and testing the weak equivalence principle.
Technically, the project will involve a lot of hands on experimental work with laser systems, precise electronics, ultra-high vacuum systems, among other techniques.