PhD scholarship in Entanglement Swapping over Long Distances using SiPh-Circuitry

Tuesday 22 Dec 20

Apply for this job

Apply no later than 7 March 2021
Apply for the job at DTU Fotonik by completing the following form.

Apply online

DTU Fotonik works with all areas of photonic engineering, including a strong focus on optical communications. We are hereby announcing a PhD position within the quantum integrated photonics. This project is part of the centre of excellence Silicon Photonics for Optical Communications (SPOC) funded by the Danish National Research Foundation and established in 2015. The SPOC centre was established to aim at significantly advancing the state-of-the-art in ultra-high capacity optical communications and this PhD project will be at the heart of this activity.

It is widely accepted that a quantum repeater will rely on quantum entanglement. Quantum entanglement sources are essential, and useful for many applications, including potential quantum repeaters, quantum computing and communications. In addition, high-dimensional entanglement offers much richer processing powers both for quantum communication and simulations. In SPOC-I we have generated a single photon-pair entangled in 15-D on a silicon chip, and a goal for SPOC-II is to generate and manipulate multiple photons entangled in high-dimensional on a chip, and transport these states from one chip to another, enabling distributed quantum computing or a quantum repeater building block.

The PhD project focuses on the realization of silicon chip-to-chip quantum entanglement swapping, one of the basic functionality of a quantum repeater, in order to extend the entangling distance between parties. The PhD student is going to design silicon photonic integrated circuit for generation of quantum entangled state, which will be fabricated in the state-of-the-art cleanroom DTU Nanolabs. After the silicon quantum chip is fabricated, the PhD student will characterize the basic performances of the chip, such as the purity, indistinguishability of single photon sources, and the fidelity of the generated quantum states. Experimental demonstration over long distance link of quantum entanglement swapping between silicon chips with high fidelity in our quantum lab will be the final target of the project.

As part of the Danish Ph.D. program the student will follow a number of Ph.D. courses and there will be an opportunity to have an external research stay at an internationally recognized group outside Denmark. To frame and support the project, DTU Fotonik has close collaborations with numerous internationally leading universities and research organizations.

Responsibilities and qualifications
In this multidisciplinary project, you will learn both integrated photonics and quantum photonics technologies, and how to generate quantum entangled state using silicon photonic integrated circuits, and increase the understand the quantum network in a real deployment. Your research task will include:

  • Design and characterization of on-chip single photon source generated by spontaneous four wave mixing.
  • Design silicon circuit to generate high dimensional entangled quantum state, and implement Bell state measurement on-chip
  • Implement phase locked-loop for long distance transmission
  • Implement silicon chip to chip quantum swapping in a long distance scenario

Furthermore, you will:

  • actively participate in the network-wide events of the SPOC, and actively collaborate with the national and international partners of the project
  • engage in DTU’s teaching activities and supervise Bachelor and Master Project students
  • participate in international conferences, compose scientific manuscripts for publications, and take part in outreach activities.

You should 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 in engineering, physics, or related fields. Documented experience with quantum information, integrated photonics, etc. will help in the positive evaluation. Preference will also be given to candidates who can document their ability for scientific publications.

We also expect that you:

  • have the ability to work focused and to achieve ambitious goals
  • are willing to develop any required skills and knowledge
  • are a good team player and proactive
  • have excellent communication skills in English - both written and spoken

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 the DTU PhD Guide.

The assessment of the applicants will be made by Senior Researcher Yunhong Ding, Assistant Professor Davide Bacco, Professor Karsten Rottwitt, and SPOC centre leader Professor Leif Katsuo Oxenløwe.

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 Senior Researcher Yunhong Ding and Assistant Professor Davide Bacco

You can read more about DTU Fotonik 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 7 March 2021 (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
  • Excel sheet with translation of grades to the Danish grading system (see guidelines and Excel spreadsheet here)

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

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

DTU Fotonik has 210 employees with competences in optics and is one of the largest centers in the world based solely on research in photonics. Research is performed within optical sensors, lasers, LEDs, photovoltaics, ultra-high speed optical transmission systems, bio-photonics, nano-optics and quantum photonics.

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 12,000 students and 6,000 employees. We work in an international atmosphere and have an inclusive, evolving, and informal working environment. Our main campus is in Kgs. Lyngby north of Copenhagen and we have campuses in Roskilde and Ballerup and in Sisimiut in Greenland.