The Royal Institute of Technology, Stockholm, pioneers quantum engineering at low temperatures
Oxford Instruments' Kelvinoxast dilution refrigerators are helping physicists at the Royal Institute of Technology, Stockholm, explore advances in solid state quantum scale computing.
The researchers are using the Kelvinoxast to achieve low temperatures necessary for the manipulation of single Cooper pairs in superconducting circuits.
The results may be useful in creating new electrical standards and quantum devices.
The Kelvinoxast, which uses Oxford Instruments's sorption pumping technology, removes the need for room temperature pumping systems to circulate the 3He/4He mixture and this brings significant benefits to the user in terms of a compact footprint and ease of use.
Explaining the research conducted using the Kelvinoxast, Professor David Haviland, Department of Physics, Royal Institute of Technology, Stockholm said, "We are measuring small capacitance Josephson junction circuits. "With these circuits we can perform interesting quantum physics experiments using the Kelvinoxast.
"We are designing a circuit and measurement system, where we can exercise quantum control of the circuit.
"We send fast pulses down to the sample at ultra low temperatures so that we can prepare a quantum state of the circuit, and read out the state of the circuit after some well defined delay.
"Such circuits are very new and at present studied by only a dozen experimental groups world-wide. "Quantum engineering is conducted in atomic and molecular physics, but we are now actually able to do this at low temperature with electronic, Josephson junction circuits. "The ability to fully design these circuits, and scale them to larger systems, could open up a way for new applications of quantum physics in the future".
The researchers at the Royal Institute of Technology need an ultra low temperature environment to conduct the experiments, which is created in the Kelvinoxast. The Kelvinoxast operates by cryogenically circulating 3He using a double sorption pump system built into the insert.
Utilising charcoal sorption pumps at cryogenic temperatures results in higher circulation rates of almost pure 3He enabling enhanced cooling power compared with conventional room temperature pumping systems.
The fully automated nature of the system makes it fast and easy to use, so that physicists can spend more time on the experiment, and less time on the refrigeration technology.
This advanced experimentation is only possible by using a dilution refrigerator like the Kelvinoxast where fascinating phenomena in physics are unravelled at ultra low temperatures of just a few 10s of milli-Kelvin.
By using this equipment, researchers such as those at Royal Institute of Technology, Stockholm, are exploiting advances at the forefront of emerging quantum electronic technologies.
