Laboratory instrumentation

Our group was formed only a few years ago with empty lab space, but we now have good access to equipment for basic experimental research at low temparatures and high magnetic fields thanks to funding from the Knut and Alice Wallenberg foundation and start-up funds from Stockholm University.

Cryostats

Our work-horse is a 17 T cryogen-free system 17 T cryostat
based on closed-cycle refrigeration. It is able to operate in the temperature range of 1.6 K to 300 K. The cryostat has a probe for 360 degree sample rotation and an ac-susceptibility AC susceptibility probe
probe. We also have a closed-cycle 3He insert for temperatures down to 300 mK (290 mK base temperature, sample in vacuum).

For low-temperature, low-field meassurements we have a cryogen-free 3He cryostat with optical access 3He cryostat with optical access
reaching 5 T.

A third cryostat for testing and zero-field measurements, we have a home-built Home-built cryostat
cryogen-free cryostat reaching about 12 K.

General instrumentation

Our general instrumentation include:

PXI system

For control and measurements, we have a state-of-the-art, real-time PXI system PXI system
from National Instruments for high-speed and high-resolution data acquisition. This versatile system will enable unique electric, thermal, calorimetric, and magnetic measurements. In particular, the system includes:

  • PXI-8196: embedded real-time controller
  • PXI-5422: 200 MS/s, 16 bit waveform generator, up to 2 GHz random interleaved
  • PXI-4461: 24 bit, 204.8 kS/s analog inputs (2), analog outputs (2)
  • PXI-4462: 24 bit, 204.8 kS/s analog inputs (4)
  • PXI-5922: 24 bit flex, 500 kS/s to 15 MS/s analog input
  • PXI-5122: 100 MS/s, 14 bit analog inputs (2), 256 Mb/ch
  • PXI-7831R: FPGA (1MGates, 40 MHz base clock), integrated with digital i/o (24 ch), 200 kS/s, analog inputs (8 ch, 200 kS/s, 16 bit), analog outputs (8 ch, 500 kS/s, 16 bit)
  • PXI-6251: M-series, 16 bit, 1.5 MS/s, digital i/o (24 ch), analog inputs (8), analog outputs (2)
The system is be combined with low-noise and/or transformer preamplifiers to yield nV-level resolution.

Measurement software

The instrumentation is integrated by means of a LabVIEW-based measurement program for automated measurements. The system currently supports:

  • VISA, GPIB, and serial communication with connected instruments
  • Waveform generation, sampling & analysis
  • Communication with the PXI system cards
  • Communication with front panel of the FPGA
  • Remote access of the 17 T magnet computer controller

Nanofabrication

For sample fabrication, the Nano-Fab Lab at AlbaNova enables fabrication of advanced devices and samples. Equipment here include, among other things, a focused ion beam, sputtering equipment, SEM and e-beam writer, mask aligner, AFM, reactive ion etcher, microscopes, surface profilometer, and resist facilities in clean-room environment. Our group (through external and internal financing) has contributed to the following equipment: