Advanced Measurement Facilities

Dilution Refrigerator

The low-temperature laboratory has upgraded its measurement facility infrastructure by acquiring a broadband Agilent microwave source which was purchased using combined funds. The MW source will be used for cutting-edge experiments in the dilution fridge, which is already set up with high frequency (up to 60 GHz) coaxial lines. This piece of equipment will prove essential for spin spectroscopy studies involving defects in semiconductors, such as silicon, III-V nanowires, quantum dots and NV- diamond devices. The closed-cycle, cryogen-free dilution refrigerator from Leiden Cryogenics (The Netherlands) was installed and commissioned in 2011. It cools a mixing chamber plate of 30cm 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 magneto-transport 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.

Optical Quantum Measurement System

The quantum measurement facility was established in 2010 and is one of the first systems in the world to 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 532nm continuous or pulsed excitation. The microscope has a diffraction limited optically spatial resolution of 250nm with 500nm 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 37°C 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 two commercial micro-Raman Spectrometers for conducting Ultra-Violet, Visible and Near Infra-Red Raman and Luminescence studies. The Renishaw RM 1000 is located within the CQC2T Cleanroom. This 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 has recently been moved from Bio21 into a new spectroscopy laboratory next to the Cleanroom. This system is integrated with a Philips XL30SEM allowing in-situ optical measurements. This system is configured with both visible (532nm) and near infrared (1064nm) excitation sources and visible and NIR (out to 1.7 μm) detection capabilities. A SULA Deep Level Transient Spectroscopy (DLTS) system and Hall system is also housed within the Melbourne node to electrically characterise devices.

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