Accepting PhD Students

PhD projects

<p>1. <strong>Flight in superfluids</strong></p>
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The project is to create and perform experiments with new types of superconducting probes for quantum liquids: precisely controllable levitators working at sub-millikelvin temperatures. Recently we have made a significant progress in the development of these instruments and we will explore several outstanding problems. </p>
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Firstly, pinning and nucleation of quantum vortices in superfluid helium-4. Currently, there are two contradictory pictures of how quantum vortices attach (‘pin’) to surfaces and how it affects their motion. A levitating sphere offers a new type of experimental topology and has the power to resolve this issue.</p>
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Secondly, the question of existence of a lift force in a superfluid remains open. We will build a hydrofoil, move it through superfluid and observe whether the lift exists.</p>
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Thirdly, the surface-bound states in superfluid helium-3, the coldest liquid in the Universe, at microkelvin temperatures represent a largely unexplored physical system with potentially extremely unusual properties. We have recently demonstrated how to probe this system by driving it out of equilibrium, and the new instruments promise to enhance our capabilities. </p>

<p>2. <strong>Superfluid ³He as an instrument for fundamental physics</strong></p>
<p>We are seeking PhD students to join our team in building and implementing experiments at temperatures significantly below one millikelvin. Our current projects include using superfluid ³He as an instrument for fundamental physics: a dark matter detector and a simulator of the early universe.</p><p>
The detector will use an ultrasensitive superfluid ³He calorimeter and superconducting transition edge sensors for achieving a high resolution in detecting spin-dependent interactions between ³He nuclei and hypothetical dark matter particles.</p><p>
The simulator will probe the dynamics of phase transitions between two superfluid states in ³He, which is found to be of surprising similarity to the hypothetical phase transitions in the quantum vacuum of the early universe. The results of the experiments will inform the interpretation of the gravitational wave signatures from processes that took place shortly after the Big Bang.</p>