Bluefors system, mK Cryostat

University of Vienna

Vienna | Website

Large equipment

Short Description

Eigenexcitations of the electron spins in magnetically ordered systems can be observed in ferro-, ferri-, and antiferromagnets and are referred to as spin waves, with their corresponding quasi-particles called magnons. The field of spin waves in magnetic materials nowadays is called magnonics and investigates the transmission, storage, and processing of information with packages of spin waves. The access to the millikelvin temperature regime, together with high-frequency microwave technology, allows first steps towards quantum magnonics and enables access to the emerging field of hybrid quantum opto-magnonic systems.

The setup comprises the vacuum can with the cryostat, and the magnet, the sample loader, the magnet power supply, high-frequency cables, and a measurement-rack including an Anritsu Vector Network Analyser (VNA) rated up to 70 GHz. The cryostat is sectioned into 4 different thermal stages: 50 K Flange, 4 K Flange, Still Flange, and Mixing Chamber.

▪ Base temperature 10 mK.
▪ 9-1-1 T superconducting vector magnet.
▪ 4 regular and 4 superconducting microwave transmission lines (active up to 65 GHz).
▪ Active vibration stabilisation.
▪ Optical access from top and bottom (via fiber).
▪ Bottom loading system (fast cooldown).

Contact Person

Andrii Chumak

Research Services

Quantum magnonics
Nanoscale magnonic circuits
Non-reciprocal 3D architectures for magnonic functionalities
Functional YIG films and microstructures
Spin-orbit phenomena and magnon spintronics
Cuvature-induced effects in magnetic nanostructures
Novel trends in superconductivity
Magnon fluxonics

Methods & Expertise for Research Infrastructure

The field of magnonics usually operates with coherent magnons at room temperature. The density of the so-called thermal magnons that are in equilibrium with a phononic bath of a solid body is around 10^18 cm^-3. Thus, the operations with single magnons are not possible without using cryogenic techniques. The most straightforward estimation using Bose-Einstein distribution shows that the thermal magnon population at 10 GHz and 100 mK is around 0.01, and nowadays mK temperatures are readily accessible with commercial dilution refrigerators. Compared to the area of quantum optics, which is already a well-established field of modern physics, magnonics offers a set of unique features inherent also to a usual room-temperature magnonics: scalability down to the atomic lattice scale, frequency range from GHz up to hundreds of THz, straightforward control of magnons by electric currents and fields, pronounced natural nonlinearity, and a manifold of nonreciprocal phenomena.

Moreover, hybrid quantum magnonics shows a promising path to bridge the gap between different quantum technologies. It offers the unique combination of spin-, phonon-, and photon- (including microwave) quantum systems and ultimately highly integrable hybrid quantum systems. Having achieved longer coherence times and lengths, integrated quantum magnonics will allow the coupling to other quantum systems, promising efficient interaction between the sub-systems and their mutual interactive characterization and examination.

Andrii Chumak
Nanomagnetism and Magnonics, Faculty of Physics
The cryostat can be used in the framework of joint scientific investigations.