Introduction

Sub-millikelvin experimental station is constructed on a commercial powerful dilution refrigerator with a home-made adiabatic nuclear demagnetization system, which can provide extreme conditions of ultra-low temperature (below 1 mK) and strong magnetic field (up to 16 T). Equipped with high-precision electrical measurement instruments including lock-in amplifiers, pre-amplifiers and low-noise source measure units, the station has a noise level as low as 10 nV by strictly multi-stage filtering and optimized grounding. This makes it an ideal measurement platform for the study of nanoscale electronics, topological quantum computing, physical property measurements and manipulations of strong correlated electron systems. At present, this station consists of adiabatic nuclear demagnetization measurement unit and dilution refrigerator measurement unit. The dilution refrigerator measurement unit is composed of a commercial top-loading dilution refrigerator, which is designed for quick sample screening for the Adiabatic nuclear demagnetization measurement.

Parameter

Characteristic

A detailed introduction to the adiabatic nuclear demagnetization measurement unit:

1.The adiabatic nuclear demagnetization system is developed by ourselves, where the nuclear stage is made of a high purity copper rod and the sample stage is made of annealed high purity silver.

2.The sample temperature in the range of sub-mK to mK can be monitored with the 3He melting curve thermometer (MCT) and Pt-nuclear magnetic resonance (NMR) thermometer.

3.The measurement wire is made of 12 pair shielded twisted pair cable. To measure weak signals accurately at ultra-low temperatures, the electrical leads each are well thermally anchored and filtered at different temperatures.

4.The user unit is equipped with precise electrical measurement instruments working at low frequency and DC, including digital source meters, lock-in amplifiers and voltage per-amplifiers, nanovoltmeter and so on.

Specifications of top-loading dilution refrigerator:

A detailed introduction to the top-loading dilution refrigerator:

1.We provide three sample probes for users: one probe equips with a rotator, and the other two are standard ones, which can be modified according to the measurement requirements.

2.The magnet is made with superconducting wires specially prepared for high field, and no flux jumping will occur.

3.Model 372 resistance bridge is applied to precisely and fast measure and control the temperature of each cold stage of dilution refrigerator.

4.The user unit is equipped with precise electrical measurement instruments working at low frequency and high frequency, including microwave signal generator, arbitrary wave generator, microwave vector network analyzer, semiconductor parameter analyzer, digital source meters, lock-in amplifiers and voltage per-amplifiers, nanovoltmeter and so on.

Glove box system:

Glove box system can realize air-sensitive devices fabricating in an inert gas atmosphere. It will fulfil the dry transferring and metal film coating of van der Waals devices and twistronics devices, and optimize device electrical performance, like high mobility and good Ohmic contact. The Glove box system provide a good platform to investigate low dimensional topological quantum states. This system offers plasma cleaning, dry transferring, metal film coating, wire bonding, and four probe electrical testing for device fabricating. 

Contact

Bingbing Tong, E-mail: tongbb@iphy.ac.cn