Apply now »

EPFL, the Swiss Federal Institute of Technology in Lausanne, is one of the most dynamic university campuses in Europe and ranks among the top 20 universities worldwide. The EPFL employs more than 6,500 people supporting the three main missions of the institutions: education, research and innovation. The EPFL campus offers an exceptional working environment at the heart of a community of more than 18,500 people, including over 14,000 students and 4,000 researchers from more than 120 different countries.

Postdoc position in HQC lab

Project description

A quantum dot (QD) embedded in a circuit quantum electrodynamics (cQED) architecture offers a promising platform for both quantum information processing and the study of fundamental light-matter interactions, as well as enabling analog quantum simulations. Recent experiments have demonstrated strong coupling in semiconducting QD-cavity hybrid devices, where resonator microwave photons interact with the charge or spin degrees of freedom in QDs via their electric dipolar interaction.

A particularly compelling direction for future research is achieving ultrastrong coupling between superconducting cavity photons and QD electrons, which could be realized by increasing resonator impedance, enhancing electric field fluctuations, and optimizing gate lever arms.

Our research focuses on double quantum dots (DQDs) defined in planar Germanium and crystal-phase-defined DQDs within InAs nanowires. The strong spin-orbit interaction (SOI) in these semiconductor materials simplifies spin qubit design, enabling rapid spin manipulation through electrical signals and eliminating the need for micromagnets.

Building on these properties, strong coupling between microwave photons and charge qubits in planar Ge, as well as charge and singlet-triplet qubits in InAs nanowires, has recently been demonstrated. These advancements pave the way for significant progress in quantum technologies, making this an exciting and impactful field of research.

Project objectives

The postdoctoral project focuses on two main goals:

  • Maximizing light-matter interaction strength: Our aim is to surpass 1 GHz coupling with the charge degree of freedom and approach the bare resonator and qubit energies (4–8 GHz), thereby achieving the ultrastrong coupling regime.
  • Using photons as a quantum bus: This will enable long-distance spin-spin entanglement, a key advancement for scalable quantum networks.

These goals will be pursued by:

  • Increasing resonator impedance through the use of superconducting Josephson junctions/SQUID arrays or ultracompact GrAl resonators.
  • Optimizing the coupling lever arm between the resonator and the double quantum dot with tailored gate designs.

Achieving ultrastrong coupling will establish a distinctive platform for exploring fundamental quantum phenomena and advancing quantum technology applications. Success in this project could unlock new research directions at the intersection of semiconductor and superconducting quantum technologies. The long-term aim is to integrate these platforms coherently, significantly broadening the scope of solid-state quantum hardware and introducing innovative strategies for quantum information technology.

Main duties and responsibilities

The successful candidate will work on integrating QD devices defined in planar Ge heterostructures and crystal-phase-defined DQDs within InAs nanowires with superconducting high-impedance resonators. Device fabrication, including manipulation and transfer of nanowires, will take place in the Center of Micro-Nanotechnology (CMi) cleanroom at EPFL, which is fully equipped with advanced tools for nanofabrication. High-quality semiconductor materials will be provided through collaborations with our project partners at Lund University and the University of Basel. The hybrid structures will be tested in a dilution refrigerator at 10 mK, using both cryogenic and room-temperature microwave electronics. The candidate will perform low-noise cryogenic and high-frequency measurements to characterize the coupling of charge and spin states in artificial atoms with the high-impedance environment. Success in this role will leverage our in-house expertise in nanofabrication, state-of-the-art microwave measurements, and the collaborative network within our research group.

Responsibilities may include:

  • Device fabrication using photolithography, electron-beam lithography, and subtractive processing techniques.
  • Manipulation and assembly of nanowires.
  • Design and layout of microwave superconducting circuits, including conceptual and physical circuit design.
  • Conducting microwave and time-domain characterization measurements.

Profile

We are seeking candidates with a strong interest in quantum technology based on semiconducting/superconducting quantum circuits. Proficiency in English, in reading, writing and discussing scientific material is essential, along with strong teamwork and excellent communication skills.

  • PhD in physics, quantum engineering, or electrical engineering, ideally with a focus on semiconducting/superconducting devices
  • Extensive experience in nanofabrication, cryogenics, microwave design, microwave measurements. Skills in fabrication of nanowire-based quantum devices would be a plus.
  • Strong general research skills with the ability to conduct independent research
  • Ability to collaborate effectively within a team and with collaborators
  • Demonstrated initiative, results-oriented mindset, organizational skills, and creativity
  • Proficiency in programming language for data analysis

We offer

  • A stimulating and international working environment
  • Competitive salary and excellent working conditions – more information can be found on our website (https://www.epfl.ch/campus/services/human-resources/en/basic-starting-salary-of-doctoral-assistants-and-postdocs/)
  • Opportunity to perform state-of-the-art research in one of the most dynamic scientific institutions in Europe.
  • Opportunity to interact with internationally renowned experts, and with a strong team of postdoctoral researchers and PhD students

Informations

Application procedure

The application should be written in English 

CV: detailing education, previous employment, publication list, and contact information for at least two references.

Personal Letter: introducing yourself, describing your previous research areas and main research achievements, and outlining your future goals and research interests.

For any further information,

- Please contact : Assistant Professor Pasquale Scarlino

- E-mail: pasquale.scarlino@epfl.ch

- Or on our web site EPFL HQC Lab :  https://www.epfl.ch/labs/hqc/open-positions/

 

Contract Start Date : as soon as possible

Activity Rate:100% 

Contract Type: Fixed Term Contract

Duration: 1 year renewable

Reference: 1202 










Apply now »