Delft WetFridge facilityWetFridges Low T Nanotech Researchfacility

Contact details:

Herre van der Zant
Lorentzweg 1, 2628 CJ Delft

The cryogenic equipment of the TU Delft WetFridge facility encompasses a substantial number of wet dilution refrigerators and Helium-4 cryostats coupled to a helium liquefier so that the helium can be reused in a cost-effective way. The facility provides an excellent setting to study nano-electronic and quantum aspects of a wide variety of materials and devices. The ultra-low temperature research environment provided within this facility enables research lines at TU Delft and other institutions in these emerging research fields.
The facility requires a high operational knowledge of the individual research stations in order to function properly; direct access to the facilities is therefore limited for external researchers. Close collaboration is expected with resident researchers to ensure optimal use of the facility and fit of particular experiments to the targeted set-ups.

This state-of-the-art facility provides an excellent setting to study nano-electronic and quantum aspects of a wide variety of materials and devices. The ultra-low temperature research environment provided within the facilities equipment enables a wide range of research lines at TU Delft and other institutions. With this facility it becomes possible to reveal new physics and to initiate novel applications of quantum effects and nano-electronics
Equipment & data
The facility consists of a central helium liquefier coupled to a large (>10) number of dilution refrigerators. The dilution refrigerator was first reduced to practice in Leiden University in 1964. Since then the dilution refrigerators have evolved for over 50 years now, leading to high quality systems with stable performance. Dilution refrigerators achieve near zero Kelvin temperatures by using the cooling power of evaporation of Helium between different Helium phases. In Delft, all wet dilution refrigerators are connected to a central system where the evaporated helium is liquefied for re-use in the facility.
Dilution refrigerators enable studying of electrical transport properties, electron wave fuctions, quantum states of new engineered materials and devices under cold conditions with the aim to eliminate environmental fluctuations. Typical experiments consist of current-voltage characteristics as a function of various external stimuli such as electrode separation, gate voltage, temperature, and/or magnetic field.
Types of research
Novel Engineered Nanostructures open up new possibilities for exploring the nature, limits, and use of quantum mechanics The facilties have a large impact on groundbreaking research, three recent examples include mechanical resonator research, single molecular devices and quantum dot networks. Gary Steele and his team succeeded in cooling a massive, millimeter-sized vibrating membrane to a temperature of only 34 microkelvin, the lowest temperature reported to date for a mechanical resonator. Herre van der Zant and his colleagues (QN) reported considerable progress with molecules and atoms as building blocks of electronic components. They designed a single molecule that functions as a resonant tunneling device, which can act as a useful building block in nanometer-size circuits Additionally they prepared atomically coherent two-dimensional percolative networks of PbSe quantum dots connected via atomic bonds where charge carriers display high mobilities.
-Nature Communications 6, 8491, 2015,
-Nature Nanotechnology 8, 830, 2014
-Nature Communications 6, 8195, 2015

Connection to strategic developments
Topsectoren: 
High Tech Systemen en Materialen
ESFRI:
Physical Sciences and Engineering
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