Advanced Measurement Facilities

Dilution Refrigerator

In May 2011, thanks to an ARC LEIF grant, a closed-cycle, cryogen-free dilution refrigerator (Fig. 5) from Leiden Cryogenics (The Netherlands) was installed and commissioned. This state-of-the-art system operates with a closed cycle and does not require any additional liquid Helium to operate. It cools a mixing chamber plate of 30 cm diameter to a base temperature of 20 mK, which provides a versatile piece of real-estate to measure a number of devices simultaneously and in one cool-down cycle. The insert is equipped with 48x DC wires, 10x flexible (<1 GHz) and 2x semi-rigid coaxes (60 GHz). The system also comes with an insertable probe to ‘quickly’ characterize electronic devices at low temperatures while maintaining a low temperature of the fridge. The probe has 36x DC wires and 2x flexible coaxes and positions the samples directly into the center of a 3D superconducting vector magnet (9-1-1 Tesla) for magnetotransport and/or anisotropy studies. Furthermore, optical windows can be fitted in the outer and inner vacuum cans to illuminate devices mounted on the probe with external light sources. Cryogenic low-pass filters and breakout boxes were constructed for signal optimization and interfacing the wiring of the probe to room temperature low-noise electronics. The Melbourne team have begun to implement 2 additional sample holders for mounting samples on the mixing chamber plate and started to assemble the parts required for radiofrequency measurements using the coax lines installed in this beautiful system. In the near future, these highfrequency cables will allow the coherent manipulation and control of quantum states on short timescales to investigate lifetime of meta-stable states.

Optical Quantum Measurement System

The quantum measurement facility was established in 2010 and is one of the first systems in the world to in incorporate quantum measurement technology with a conventional biological microscope. The system supports the Centre’s work on quantum sensors. The optical microscope has confocal and wide field imaging capability and is operated with 532 nm continuous or pulsed excitation. The microscope has a diffraction limited optically spatial resolution of 250 nm with 500 nm to several micron lateral resolutions depending on the mode of operation. The microscope is equipped with single photon counting detectors (Perkin & Elmer) and an sCMOS CCD camera (Andor) which provides single molecule detection capability. The entire system is in a temperature controlled environment which can be operated and maintained from room temperature up to 37oC ensuring living cells can be imaged in a controlled and functional environment. Humidity and CO2 control of the environment is also available using a custom stage and controller (Clear state solutions). The system is used to image and track single defect centres in nanodiamonds which have been ingested into living cells. The quantum measurement interface can also control the single electron spin of these single optical defect centres using microwaves and traditional RF technology. The system is controlled and operated using a custom built interface which allows the user to implement a myriad of quantum measurements on the nanodiamond system, all whilst in the confines of a living cell.

Advanced Spectroscopy

The Melbourne Node is home to three commercial micro-Raman Spectrometers for conducting Ultra-Violet, Visible and Near Infra-Red Raman and Luminescence studies. The systems are located in the Pelletron (30m2) Laboratory (Dilor XY), the CQC2T Cleanroom (Renishaw RM 1000) and the Bio21 Molecular Science and Biotechnology Institute (Renishaw Invia Reflex). The Dilor system is a triple grating, high resolution spectrometer with a diode pumped, frequency doubled, solid-state excitation source. The Renishaw RM1000 system is a single grating, extended wavelength Raman/ luminescence spectrometer (244 - 1000nm) with Coherent I90 FRED, Kimmon HeCd and Stellar Pro Modulaser excitation sources. The Renishaw Invia Reflex system is configured with both visible (532nm) and near infrared (1064nm) excitation sources and was fully commissioned in 2008. The Melbourne node also maintains strong links with the ion beam facilities at the Australian National University.

The JEOL UHV AFM with Surface Spectroscopy Facility is located in a separate room within the Cleanroom complex.