The London Low Temperature Laboratory is a centre for fundamental research in the mK and μK temperature regime and the development of new instrumentation and thermometry.
The London Low Temperature Laboratory at Royal Holloway is part of the European Microkelvin Platform (EMP), which is funded as a European Advanced Infrastructure by Horizon 2020. Within the Infrastructure Programme, the EMP links ~20 leading European ultralow-temperature university physics departments, national laboratories and related technology and industry partners. The EMP aspires to create “a major European ‘laboratory without walls’ in the field of ultralow temperatures”. The individual members offer a varied and comprehensive portfolio of experimental expertise, with eight opening their facilities to external researchers who lack their own infrastructure.
The Low Temperature Laboratory at RHUL was founded in 1986 as part of a reorganisation of the University of London, with a purpose-built laboratory space of 130 m2. It has a long tradition of research in the microkelvin regime, and is currently equipped with four nuclear demagnetization cryostats. With expansion of activity over the years, the laboratory space now stands at 555 m2, of which 180 m2is double height. The laboratory is supported by a helium liquefier installed in 2000. These infrastructure developments were funded by national strategic funds managed by HEFCE, with investment over 5 calls over a period of 20 years. The last investment was jointly sponsored by Oxford Instruments, through a strategic partnership, and the laboratory was renamed London Low Temperature Laboratory in 2011. We made the first demonstration of the feasibility of nuclear demagnetization on a cryogen-free dilution refrigerator in 2013, in collaboration with Oxford Instruments. The long research traditions of the laboratory strongly feature novel instrumentation development of wide applicability, including the pioneering work on: current sensing noise thermometry; SQUID NMR; quantum nanofluidics. In 1996 the Centre for Nanoelectronics was initiated at RHUL. Since 1998 we have operated a semi clean room, equipped with a electron beam lithography facility and associated equipment. All experimental activity is supported by a team of highly skilled technicians in our adjacent mechanical workshop (220 m2).
The in-house low temperature physics research includes experimental and theoretical studies of: refrigeration, cryogenics and thermometry in the liquid helium range and below; topological quantum matter; low dimensional quantum fluids and solids as model systems for condensed matter physics; cooling two-dimensional electron gases to ultra-low temperatures (in collaboration with Cambridge and LCN); superconducting quantum devices and sensors; ultrasensitive nanomechanical cryosensors; metrology. The latter strand is pursued in collaboration with the National Physical Laboratory, Teddington (< 30 min. drive away), with which we established a strategic partnership in 2011, and two joint appointments at full Professor level.
The laboratory is supported by EPSRC, the European Commission (FP7), and Oxford Instruments Nanoscience.
The key cryogenic facilities within the London Low Temperature Laboratory are described below. The nanotechnology fabrication facilities are detailed here.
|ND1||Wilson building (W061)||Nuclear adiabatic demagnetization refrigerator. Equipped with state-of-the-art SQUID based amplifiers. Reconstructed with two enlarged footprints for measurements at 100μK and 200μK. Experiments focused on studies of low dimensional systems, and applications of mechanical resonators, sensor development.|
|ND2||Wilson building (W060)||Nuclear adiabatic demagnetization refrigerator. Equipped with state-of-the-art SQUID based amplifiers, 3T high homogeneity NMR magnet. Experiments focused on topological superfluids, quantum nanofluidics, nanoelectromechanical resonators, thermometry, sensor development.|
|ND3||Wilson building (W060)||Nuclear adiabatic demagnetisation refrigerator, equipped with 9T sample magnet. Experiments focussed on transport measurements, cooling of new materials and nanostructures, nanoelectromechanical resonators, thermometry, strongly correlated quantum matter.|
|ND4||Wilson building (W157)||Dry nuclear adiabatic demagnetization refrigerator. Rapid prototyping of experiments down to 0.6 mK. Converted from standard Triton 200 in collaboration with Oxford Instruments.|
|PPMS||Tolansky building (T108)||Physical Properties Measurement System (Quantum Design) for materials characterization in magnetic fields < 9T and temperatures >1K.|
|Bluefors||Wilson building (W057)||Dry dilution refrigerator with < 10mK base temperature. Experiments focussed on quantum measurement and metrology|
|DRs||Wilson buildings (W060, W061, W056, W057)||Seven further conventional dilution refrigerators. (i) with sample to-loading facility, to <10 mK (ii) with 3T NMR quality magnet, to < 20 mK (iii) three dilution refrigerators, configured for microwave studies to 20 GHz, focussed on quantum devices and sensors (iv) dilution refrigerator, to < 10mK, with 14 T sample magnet (vi) small dilution refrigerator with 20 mK base temperature, access focussed on SQUID NMR on strongly correlated electron systems.|
Nuclear adiabatic demagnetization refrigerator in W061. Equipped with state-of-the-art SQUID based amplifiers. Reconstructed with two enlarged footprints for measurements at 100μK and 200μK. Experiments focused on studies of low dimensional systems, and applications of mechanical resonators, sensor development.
Senior Research Officer:Dr. Jan Nyéki
Academics: Prof. John Saunders, Dr. Andrew Casey
Current Students: Jan Knapp (started in 2017)
Recent Graduates: Alexander Waterworth (2018), Frank Arnold (2015), Kris Kent (2014)
Nuclear adiabatic demagnetization refrigerator in W060. Equipped with state-of-the-art SQUID based amplifiers, 3T high homogeneity NMR magnet. Experiments focused on topological superfluids, quantum nanofluidics, nanoelectromechanical resonators, thermometry, sensor development.
Phase Diagram of the Topological Superfluid 3He Confined in a Nanoscale Slab Geometry, L. V. Levitin, R . G. Bennett, A. Casey, B. Cowan, J. Saunders, D. Drung, Th. Schurig, J. M. Parpia, Science 340, 841-844 (2013)
Nuclear adiabatic demagnetization refrigerator in W060. Equipped with state-of-the-art SQUID based amplifiers, and 9T - 9T pair of superconducting magnets for demag and high field experimental region. Experiments focused on the ultra-low temperature properties of 2DEGs for nanoelectronics based quantum technologies.
EPSRC programme grant: Nanoelectronic Based Quantum Physics- Technology and Applications. In collaboration with London Centre of Nanotechnolgy and the University of Cambridge. More information on the project webpage.