Background
Systems of ultracold atoms have been shown to be able to measure forces. These measurements are extremely precise, and have been proposed for a variety of uses, including space exploration. The way a cold atom sensor works is usually through interferometry: a cloud of atoms is sent through a beam splitter, one part of the beam picks up a slightly different phase than the other because it is affected by an external force, which is then visible in the position of interference fringes after a second beam splitter. This is essentially a classical interferometry setup, though with atoms rather than photons.
It is well known that the performance of quantum sensors can be drastically improved with entanglement. Cold-atom sensors do not currently make targeted used of entanglement. This project theoretically and numerically investigates whether it is possible to enhance sensor performance using entanglement.
Method
This project starts with the results from, which provide a concrete interferometry setup for a cold-atom quantum sensor. The aim is to combine these results with existing results on entanglement generation using either: squeezing through one-axis twisting or two-axis countertwisting and (time permitting) quanutm non-destructive measurements, to investigate which could realistically be implemented in experiments. This requires a careful understanding of entanglement generation in real systems, including analytic and numerical work, but would ideally also be combined with an interest in understanding experimental protocols. We have some existing notes, prepared by a previous summer student, which could serve as basis for this investigation. We are in touch with experimentalists in this field, who would be happy to provide feedback on any proposed experimental protocol to generate useful entanglement in the cold atom clouds. If this is successful, it could have a very significant impact, as it could lead to one of the first quantum sensors achieving better scaling through entanglement.
Milestones
- Understand interferometry in a cold atom setup
- Reproduce results from numerically, as well as existing notes
- Understand different proposals for generating entanglement
- Investigate which of these could feasibly be used in a real cold atom setup
Courses relevant from the bachelor's degree:
Recommended courses for theoretical curriculum in the master's programme: