Cryogen-free dilution refrigerator with a 14T magnet with fast sample loading mechanism

We are seeking to purchase a dry, cryogen free, cryostat for electronic transport measurements of nano-electronic device such a graphene etc. at ultra-low temperatures (<10mK) and ultra-high, direc-tion dependent, magnetic fields (B=14T). The instrumentation shall permit a device environment with a stable (<5mK fluctuations) ultra-low base temperature (T ~ 10mK) and rapid and continuous tempera-ture control from base temperature up to T ~ 10K. The dilution refrigerator system must be equipped with full quantum transport measurement capabilities. This entails DC transmission lines, filters and breakout boxes. The specificity of this dilution refrigerator system will be its high accessible transverse magnetic field (up to 14T). The system should also have a fast sample loading mechanism, that allows a fast sample turn around time, without the need to warm up the entire system.

Quantum materials are novel systems, engineered in laboratories, which host strong enough electron-ic interactions to display quantum phenomena such as superconductivity, correlated insulating states and magnetism with tremendous technological applications. These phenomena emerge when the elec-tronic interaction dominate over the thermal fluctuations of the system, i.e. at mK temperatures. Ex-perimentally, these temperatures are reached in dilution refrigerator systems. Consequently, we aim to add such a dilution refrigerator, capable of a base temperature of 10 mK and equipped with a 14T superconducting magnet. The ultra-high 14T magnetic field will allow us to introduce a new quantizing energy scale to the material, and thus to tune the electronic interaction. In particular, this field will be high enough to condense all the electronic carriers of a variety of quantum materials into a single en-ergy level, causing the electronic spectrum to become analogous to a one-dimensional system which is highly sensitive to perturbations. Attaining this ultra-quantum limit permits the emergence of novel phenomena such as charge/spin density waves and quantum Hall effect.
This refrigerator system will thus open a completely new axis of research. It will allow to probe the electronic response to the temperature and field constraints through 48 highly-filtered DC transmis-sion lines designed to suppress electromagnetic heating of the electrons with an output integrated in our measurement setup made of an array of DC pre-amplifiers and lock-in amplifiers. The fast loading mechanism is crucial to optimize our usage of this system by greatly reducing loading times. Finally, we wish to buy a cryogen-free system both for its simplicity of usage and the low cost of operation.