Research
Topological Mesoscopic Superfluidity
At the forefront of our investigations lies the exploration of topological mesoscopic superfluidity using confined superfluid 3He. By confining superfluid 3He in precisely engineered nanofluidic sample chambers, we investigate the interplay between symmetry and topology in this unique material. Our goal is to identify and explore new states of topological quantum matter, leveraging the profound influence of confinement to create hybrid nanostructures and induce new superfluid phases.
Superconducting Quantum Circuits
Our research group focuses on studying and developing superconducting quantum circuits, which are at the forefront of quantum computing and quantum information processing. By employing innovative cooling techniques, such as immersing the circuit in liquid 3He, we effectively reduce noise and energy losses caused by material defects, thus enhancing the coherence and performance of quantum circuits. Through our work, we aim to overcome the limitations posed by temperature-induced noise and propel the practicality of quantum computers.
Quantum Materials
Within our research group, we delve into the fascinating realm of quantum materials. By manipulating atomically layered thin films of helium on graphite and employing diverse techniques at ultralow temperatures, we investigate topics such as the survival of Fermi liquids in strictly 2D systems, interacting coupled 2D fermion-boson systems, the realization of a model quantum spin liquid in 2D 3He, the interplay between superfluid and density wave order, as well as studies involving helium on graphene.
Heavy Fermion Superconductivity
We investigate heavy fermions superconductivity, focusing on YbRh2Si2, a new superconductor, which has numerous interesting features, and is a candidate for spin-triplet topological superconductivity. Our goal is to identify the nature of this superconducting order, employing micro-structuring, novel measurement techniques, and leveraging nuclear magnetism, strain, magnetic field, and temperature effects.
Cooling Electrons
At our laboratory, we focus on the cooling and measurement of diverse electron systems to ultra-low temperatures. This breakthrough enables the exploration of fragile exotic ordered states arising from electron correlations in various quantum materials and mesoscopic devices. By employing ultra-sensitive SQUID magnetometers, we achieve low dissipation measurements critical to our research. Notably, we have successfully cooled two-dimensional electrons in semiconductor heterostructures to close to 1mK using a cooling-through-the-leads approach in a 3He immersion cell, meticulously eliminating sources of heat input.
NEMS
By leveraging nanofabricated structures with dimensions similar to superfluid 3He cooper pairs, NEMS enable the exploration of quantum fluids. Our research focuses on developing low dissipation measurement techniques to accurately read out NEMS motion. Through advanced fabrication techniques and material exploration (graphene, SiN, metallic resonators), we aim to optimize NEMS for achieving long coherence times, and high sensitivity.
ULT Engineering and Technology
Our research group tackles the challenge of achieving and measuring temperatures in the range of 10 to 1 millikelvin, a critical range for various applications. Through partnerships with industry leaders like Oxford Instruments and National Measurement Institutions, we have developed advanced refrigeration systems and temperature measurement technologies. This innovation impacts manufacturing, metrology, and commercial quantum computing, driving advancements in cryogenics, international temperature standards, and the primary market for ultra-low temperatures.
Superfluid Optomechanics
Our research group explores the potential of superfluid helium as a material for building mechanical resonators with ultra-low energy dissipation, enabling long-lasting quantum states. By leveraging nanofabrication techniques, we engineer precise structures to confine superfluid helium in nanoscale volumes, generating high-frequency superfluid acoustic resonances. The insights gained from this research have broad applications in sensing, quantum simulators, and quantum information processing, advancing our understanding of quantum mechanics in engineered mechanical systems.