Denmark : PhD scholarships (2) in Modeling of Single-Photon Sources using a Modal Method

 The Nanophotonics Theory & Signal Processing Group at DTU Fotonik, Department of Photonics Engineering at the Technical University of Denmark is seeking 2 candidates for PhD positions in the field of design and simulations of highly efficient solid-state sources of single indistinguishable photons. The position is funded by the Sapere Aude DFF Starting Grant “Linear Optics Quantum Information Technology (LOQIT).

Solid-state sources of single photons are expected to play an important role in various quantum information applications, such as secure communications, quantum computation and metrology. These applications generally require near-unity efficiency and a high single-photon purity as well as indistinguishable photon emission. Furthermore, the ideal single-photon source (SPS) should be deterministic and not involve heralding or spontaneous downwards conversion. A potential platform for such a source is a quantum emitter, e.g. an InAs quantum dot, embedded in a semiconductor material. However, in a bulk material, the symmetry of the quantum dot leads to light emission in all directions. A big challenge in realizing an efficient source is thus establishing control of the light emission.

The PhD students will participate in a project team, which will design SPSs meeting all the requirements of the quantum information applications. The designs will be based on the photonic nanowire, the micropillar and the photonic crystal membrane platforms. The calculations will be performed using the modal method, representing state-of-the-art in optical simulations of single-photon sources. The fabrication and characterization of the sources will take place with external world-leading fabrication partners at CEA Grenoble, the University of Würzburg and at the Niels Bohr Institute.

The team will be employing the modal method for the calculations, and the PhD students will initially work on on the construction of open geometry boundary conditions and an adaptive spatial resolution formalism for the modal method. The formalisms will then be employed in the modeling tool used by the team to analyze and propose novel SPS designs, that realize a good compromise between the simultaneous requirements of high indistinguishability, high efficiency and high purity while representing a robust and manufacturable design.

The candidates are thus expected to


  • Construct modal-method simulation techniques implementing both semi-analytical and Fourier expansion descriptions of the eigenmodes.
  • Build open boundary formalisms converging towards the true open geometry limit for both the semi-analytical and the Fourier expansion descriptions.
  • Build an adaptive spatial resolution formalism for improving convergence in high-index contrast geometries.
  • Employ the modal method to analyze and propose new single-photon source designs to be fabricated by the external partners.

Candidates should have a master’s degree in engineering or a similar degree with an academic level equivalent to the master’s degree in engineering.

Approval and Enrolment
The scholarships for the PhD degree are subject to academic approval, and the candidates will be enrolled in one of the general degree programmes of DTU. For information about the general requirements for enrolment and the general planning of the scholarship studies, please see the DTU PhD Guide.

The assessment of the applicants will be made by Associate Professor Niels Gregersen and Professor Jesper Mørk.

We offer
We offer an interesting and challenging job in an international environment focusing on education, research, public-sector consultancy and innovation, which contribute to enhancing the economy and improving social welfare. We strive for academic excellence, collegial respect and freedom tempered by responsibility. The Technical University of Denmark (DTU) is a leading technical university in northern Europe and benchmarks with the best universities in the world.

Salary and appointment terms
Salary and appointment terms are consistent with the current rules for PhD degree students. The period of employment is 3 years. The workplace is DTU Fotonik at the DTU Lyngby campus.

Further information Further information may be obtained from Associate Professor Niels Gregersen,, tel.: +45 4525 3789 or Professor Jesper Mørk,, tel.: +45 4525 5765.

See also the project webpage: (operational early September).

You can read more about Department of Photonics Engineering on

Please do not send applications to this e-mail address, instead apply online as described below.

Please submit your online application no later than October 15, 2014.Applications must be submitted as one pdf file containing all materials to be given consideration. To apply, please open the link “Apply online,” fill in 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.

Further Information

Application Deadline : 15 October 2014

Leave a Reply

Your email address will not be published. Required fields are marked *