PhD scholarship in Multipartite Continuous-Variable Quantum Key Distribution with Squeezed Light

Monday 20 Dec 21

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Apply no later than 31 January 2022
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Continuous-variable quantum key distribution (CV-QKD) is a well established technology to distribute secret keys between two parties for data encryption. The technology has strong similarities to coherent optical telecommunication, however noise is crucial as it is attributed to an eavesdropper and, thus, drastically reduces performance. Within this position you will experimentally investigate CV-QKD with squeezed light in a multipartite setting where more than the typical two players are involved.

You will generate squeezed states of light and implement proof-of-principle experiments in the lab to demonstrate multipartite CV-QKD in various network topologies. The PhD project includes an external stay at an international research institution, and you will work together with our theory collaborators from Palacky University Olomouc in the Czech Republic as well as the Danish telecommunication infrastructure operator, TDC NET.

Responsibilities and qualifications
We are looking for a highly motivated candidate who will perform experimental demonstrations of multipartite continuous-variable quantum key distribution with squeezed light in networks. You will

  • experimentally generate squeezed and entangled states at 1550 nm using a parametric down-conversion source
  • experimentally demonstrate CV-QKD and similar protocols with multiple users using squeezed states

You have a passion for photonics and you are familiar with I/Q (amplitude / phase) modulation, be it from a background in telecommunications, quantum optics with continuous variables, interferometry or similar and you are intrigued by its application in quantum key distribution. You enjoy finding clever solutions to difficult problems and further you have the following qualifications:

  • Experience with lasers, amplitude and phase modulation and coherent detection
  • Experience with fiber optics is a plus
  • Basic experience with optical telecommunication systems is a plus (but not a requirement) since the CV-QKD system uses typical digital-signal-processing chains of telecommunication
  • Experience with python or matlab programming
  • Experience with squeezed light is not required and can be obtained during the PhD project.

You must have a two-year master's degree (120 ECTS points) or a similar degree with an academic level equivalent to a two-year master's degree.

Approval and Enrolment
The scholarship for the PhD degree is subject to academic approval, and the candidate will be enrolled in one of the general degree programmes at DTU. For information about our enrolment requirements and the general planning of the PhD study programme, please see DTU's rules for the PhD education. 

We offer
DTU is a leading technical university globally recognized for the excellence of its research, education, innovation and scientific advice. We offer a rewarding and challenging job in an international environment. We strive for academic excellence in an environment characterized by collegial respect and academic freedom tempered by responsibility.

Salary and appointment terms
The appointment will be based on the collective agreement with the Danish Confederation of Professional Associations. The allowance will be agreed upon with the relevant union. The period of employment is 3 years.

You can read more about career paths at DTU here

Further information
Further information may be obtained from Assoc. Prof. Tobias Gehring,

You can read more about DTU Physics at

If you are applying from abroad, you may find useful information on working in Denmark and at DTU at DTU – Moving to Denmark.

Application procedure

Your complete online application must be submitted no later than 31 January 2022 (Danish time)Applications must be submitted as one PDF file containing all materials to be given consideration. To apply, please open the link "Apply online", fill out the online application form, and attach all your materials in English in one PDF file. The file must include:

  • A letter motivating the application (cover letter)
  • Curriculum vitae
  • Grade transcripts and BSc/MSc diploma including official description of grading scale

You may apply prior to ob­tai­ning your master's degree but cannot begin before having received it.

Applications received after the deadline will not be considered.

All interested candidates irrespective of age, gender, race, disability, religion or ethnic background are encouraged to apply.

The position will be hosted by the Section of Quantum Physics and Information Technology (QPIT) at the Department of Physics of the Technical University of Denmark (DTU). QPIT's vision is to understand, engineer and control complex quantum systems of light and matter, and to exploit these systems for quantum information processing and quantum metrology. We are a large, highly international research group of students and staff with diverse backgrounds. We have a friendly and dynamic research environment with close, daily interaction among all group members and strong collaborations with many academic and industrial partners. Technical support is excellent with electronics and process engineers embedded in the section and a large capacity, skilled mechanical workshop at the Department.

Technology for people
DTU develops technology for people. With our international elite research and study programmes, we are helping to create a better world and to solve the global challenges formulated in the UN’s 17 Sustainable Development Goals. Hans Christian Ørsted founded DTU in 1829 with a clear vision to develop and create value using science and engineering to benefit society. That vision lives on today. DTU has 12,900 students and 6,000 employees. We work in an international atmosphere and have an inclusive, evolving, and informal working environment. DTU has campuses in all parts of Denmark and in Greenland, and we collaborate with the best universities around the world.