PhD researcher on Design and characterization of quantum devices for Qubit implementation

Leuven - PhD
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In the last decades, the continuous drive towards miniaturization of conventional MOSFETs has been accompanied with serious concerns regarding the end-of-scaling era. As technology is hitting the physical and material limits, a large effort has been put on the development of an alternative computing paradigm based on the coherent manipulation of quantum objects. In this context, impressive advances were made on the implementation of Charge, Spin, Phase and Flux Quantum Bits or Qubits [1]-[5].

The quest for different Qubit implementation has come together with the major challenge of controlling the sources of de-coherence of the quantum system. In fact, a long coherence time for the evolution of the quantum state is one of the pre-requisite for taking advantage of the unprecedented computing parallelism derived from the superposition principle. Although possible routes exists for decoupling the quantum system from parasitic sources of de-coherence (for instance embedding the qubit in a non-interacting environment like e.g. electron spins in Silicon), low-frequency noise caused by random switching of 2-level fluctuators in the close vicinity of the quantum object are one of the main extrinsic sources of de-coherence. For any qubit implementation it is then of paramount importance being able to evaluate and eventually mitigate the impact of all possible sources of de-coherence arising from materials and processing technology. 

In this respect, different approaches can be implemented : on one side, we  aim at the optimization of the synthesis of low-defectivity materials and on the other side, a strong effort will be put on the mastering of the required processing steps for the fabrication of Quantum devices with a robust quantum degree-of-freedom.

The candidate is expected to work in close relationship with engineers and physicists for the design, fabrication and characterization of quantum circuits featuring  possible implementations of Qubits. The student will take advantage of the state-of-the-art imec facilities comprising a 200mm cleanroom with a  flexible environment for device  prototyping, together with a physical/electrical characterization platform.

[1] J.J. Pla et al., Nature 489 541 (2012); Nature 496 334 (2013)
[2] J. T.  Muhonen et al.Nature Nano 9, 986 (2014)
[3] M.Steffen et al., Science 313 1423 (2006)
[4] Y.Nakamura et al., Nature 398 786 (1999)
[5] R.Hanson et al., Reviews of Modern Physics 79 4 (2006)

Type of work:

70% experimental work 20% technology study 10% literature search.

Supervisor: Iuliana Radu and Marc Heyns

Daily advisor: Massimo Mongillo

When you apply for this PhD project, mention the following reference code in the imec application form: ref. STS 1704-01.