Topological Superfluid 3He

Topological mesoscopic superfluidity of 3He 

Superfluid 3He is one of the most exciting and rich condensed matter systems we know. Over the past thirty years its intellectual impact has been felt in areas as diverse as unconventional superconductivity, cosmology and turbulence. Our recent research has taken superfluid 3He into a new regime, through its confinement on the nanoscale in well characterized nanofluidic sample chambers [1-3], exploiting new sensitive NMR techniques [4]. The influence of confinement is profound and we expect to identify and explore new states of topological quantum matter, opening a new chapter in quantum fluids research. 

Figure 1 - 3D representation of one of our typical nanofluidic confinement geometries. 

In this project, we exploit superfluid 3He, known to support two distinct topological superfluid phases in bulk, establishing the new research direction of topological mesoscopic superfluidity. Under nanoscale confinement, this material provides a unique model for topological superconductivity. The subtle interplay between symmetry and topology in these materials is an open question. Our approach will be to confine 3He in precisely engineered geometries to create hybrid nanostructures, allowing a degree of control that is unprecedented. Confinement and periodic structures, with liquid pressure as a tuning parameter of Cooper pair diameter, will induce new superfluid phases, for which the order parameter symmetry will be inferred from nuclear magnetic resonance. These materials will be building blocks for hybrid mesoscopic superfluid systems. 

Figure 2 - 3D schematic of hybrid mesoscopic superfluid 3He structure: nanofluidic SNS and NSN junctions 

1. L. V. Levitin, R. G. Bennett, A. Casey, B. Cowan, J. Saunders, D. Drung, T. Schurig and J. M. Parpia, Science 340 (6134), 841-844 (2013). 
2. L. V. Levitin, R. G. Bennett, E. V. Surovtsev, J. M. Parpia, B. Cowan, A. J. Casey and J. Saunders, Phys Rev Lett 111 (23), 235304 (2013). 
3. L. V. Levitin, R. G. Bennett, A. Casey, B. Cowan, J. Saunders, D. Drung, T. Schurig, J. M. Parpia, B. Ilic and N. Zhelev, Journal of Low Temperature Physics 175 (5-6), 667-680 (2014). 
4. L. V. Levitin, R. G. Bennett, A. Casey, B. P. Cowan, C. P. Lusher, J. Saunders, D. Drung and T. Schurig, Applied Physics Letters 91 (26), 262507 (2007). 

1. L. V. Levitin, R. G. Bennett, A. Casey, B. Cowan, J. Saunders, D. Drung, T. Schurig and J. M. Parpia, Science 340 (6134), 841-844 (2013). 
2. L. V. Levitin, R. G. Bennett, E. V. Surovtsev, J. M. Parpia, B. Cowan, A. J. Casey and J. Saunders, Phys Rev Lett 111 (23), 235304 (2013). 
3. L. V. Levitin, R. G. Bennett, A. Casey, B. Cowan, J. Saunders, D. Drung, T. Schurig, J. M. Parpia, B. Ilic and N. Zhelev, Journal of Low Temperature Physics 175 (5-6), 667-680 (2014). 
4. L. V. Levitin, R. G. Bennett, A. Casey, B. P. Cowan, C. P. Lusher, J. Saunders, D. Drung and T. Schurig, Applied Physics Letters 91 (26), 262507 (2007).