Post doctoral position in Physics - Hiring in process/Finished, not possible to apply

The Division of Atomic Physics at the Faculty of Engineering (LTH), Lund University, Sweden has a staff of over 50 researchers including guest researchers and graduate students. The research at the division is mainly based on the use of lasers, ranging from diode lasers to terawatt lasers at the High-Power Laser Facility. Some areas of research are: basic atomic physics including interactions between intense laser-fields and matter and VUV/XUV laser spectroscopy, quantum electronics, quantum optics and solid state spectroscopy, applied molecular spectroscopy, laser applications in medicine and biology, and industrial applications. More information can be found at www.atomic.physics.lu.se/.

This announcement is linked to the Quantum Information Group at the Division of Atomic Physics. The group works on the development of hardware for quantum computing and quantum memories and on developing materials where the speed of light can be slowed by 3-5 orders of magnitude for applications in e.g. laser frequency stabilization and medical imaging and treatment.

The group has a strong activity in quantum information and quantum optics based on light-matter interactions in inorganic crystals doped with rare earth ions. These materials have unique properties as solid state quantum materials due to their exceptionally narrow optical line widths, which also translates to an ability to remain in quantum superposition states over extended periods of time. Rare-earth–ion-doped crystals are also, together with trapped ions and superconducting qubits, one of three quantum computing schemes supported in the first round of the European Union Flagship on Quantum Technology. The group has been a pioneer in introducing quantum memory schemes in rare-earth-ion-doped crystals, a field in which many groups are active today. We have pioneered sophisticated structuring of the inhomogeneous absorption profiles of rare earth-ion doped crystals using optical pumping methods. Recently this has been used to control the speed of light in the crystals. The group has lately attracted considerable external funding for working in these areas and we are expanding our activities

Subject description
Depending on the experience and interest of the candidate a holder of the position could be involved in one or several of the different research project areas briefly described below.

Area 1: Laser stabilization using slow light cavities.
The frequency stability of lasers locked to reference cavities is presently limited by the thermal Brownian motion of the atoms constituting the reference cavities, which causes the length of the cavity to fluctuate with time. The current limit for the average cavity length variation is ~0.1 proton radius. We have demonstrated that slow light effects in Fabry-Pérot type cavities made of rare-earth-ion-doped crystal materials can decrease cavity mode spacing and line widths by 3-5 orders of magnitude. Further, we have shown that in such cavities the effect of length fluctuations on the cavity resonance frequency is decreased by 3-5 orders of magnitude compared to a conventional vacuum cavity of the same length. This project aims to explore this quite remarkable feature of such cavities for improving laser frequency stabilization beyond the current limits.

Area 2: development of new techniques for optical deep tissue imaging and medical treatment beyond what is possible today
This project presents a unique opportunity to work at the border between advanced atomic physics and applied medical imaging. The spatial resolution of tissue diagnostics using optical techniques is limited by the strong light scattering properties of tissue. However, if an ultrasound pulse with frequency fUS is focused in tissue, light with frequency fL traversing a volume occupied by the ultrasound pulse can be tagged by having its frequency shifted to fS = fL+fUS. By analyzing only the frequency shifted light, a spatial resolution equal to the ultrasound focus can be obtained. A critical factor is then the ability to discriminate between the light frequency-shifted by the ultrasound and the much stronger non-frequency-shifted light. Based on our techniques to quantum engineer narrowband filters where the group velocity of light is decreased to a few km/s we have developed strongly frequency discriminating, time-delaying, wide acceptance angle filters that can push, deep tissue imaging significantly beyond what is possible today. This project aims at, in cooperation with researchers in electro-magnetic field propagation, medicine and bioengineering, develop methods reaching even further into tissue using digital and optical phase conjugation techniques. This can have significant impact as optical imaging has a molecular sensitivity lacking in conventional medical imaging such as MRI, X-rays or pure ultrasound.

Area 3: Experimental quantum information in rare-earth-ion doped crystals
Quantum information in general concerns the science of utilising quantum systems and the laws of quantum mechanics to get a performance better than can be obtained with classical information devices and techniques. Our quantum hardware is inorganic crystals doped with rare earth ions. As a solid state system rare-earth-ion doped crystals are unique because of their millisecond optical coherence times, i.e. several orders of magnitude longer than in most other solid state systems. Further, they can have spin coherence times of more than 6 hours. There is also a strong and controllable dipole-dipole interaction between ions close to each other in space and this interaction can provide reliable quantum gate operations. Current work includes developing a capability to read out the quantum state of individual rare earth ions in rare-earth-ion doped crystals and development of high fidelity quantum gate operations. The work includes using extensive spectral tailoring and quantum state preparation using control tools that we have available, combined with developing and refining single ion detection techniques in rare-earth ion doped materials. Several approaches to this are investigated, including enhancing the emission from ions by using the Purcell effect in high finesse micron-sized cavities.

Work duties
The main duties involved in a post-doctoral position is to conduct research. However, teaching can also be included and the position also includes the opportunity for courses in higher education teaching and learning.

The postdoctoral researcher is expected to assist in supervision of degree projects and in part also in supervision for postgraduate students. Depending on his/her experience we may also offer the candidate training in applying for external funding. For the interested candidate we also expect to have outreach projects such that the postdoctoral researcher could collect experience from such tasks.

Qualification requirements
Appointment to a post-doctoral position requires that the applicant has a PhD, or an international degree deemed equivalent to a PhD, within the subject of the position, completed no more than three years before the last date for applications. Under special circumstances, the doctoral degree can have been completed earlier.

Additional requirements:

• Extensive experience in experimental laser-based research of relevance for the research project areas.
• Very good oral and written proficiency in English.
• Ability to run projects independently and ability to interact efficiently with other members in a research team.

Assessment criteria and other qualifications
This is a career development position primarily focused on research. The position is intended as an initial step in a career, and the assessment of the applicants will primarily be based on their research qualifications and potential as researchers. Particular emphasis will be placed on research skills within the subject.

For appointments to a post-doctoral position, the following shall form the assessment criteria:

• A good ability to develop and conduct high quality research.
• Teaching skills.

Additional assessment criteria:

• Strong and well documented research experience of relevance for one or several of the research project areas. 

Consideration will also be given to good collaborative skills, drive and independence, and how the applicant’s experience and skills complement and strengthen ongoing research within the research group, and how they stand to contribute to its future development.

Terms of employment
This is a full-time, fixed-term employment of a maximum of 2 years. The period of employment is determined in accordance with the agreement “Avtal om tidsbegränsad anställning som postdoktor” (“Agreement on fixed-term employment as a post-doctoral fellow”) between Lund University, SACO-S, OFR/S and SEKO, dated 4 September 2008.

Instructions on how to apply
Applications shall be written in English. LTH uses a special qualifications portfolio to report and document qualifications. Write the application in accordance with the following outline and attach it as three PDF files (in the recruitment system). Read more here: www.lth.se/english/working-at-lth/to-apply-for-academic-positions-at-lth/

The portfolio at the web address above is used for postdoctoral positions as well as for higher academic position. All parts of the requested information may therefore not be fully relevant for the present position. You are therefore advised to fill in the forms to the extent that you deem relevant based on your experience and the requirements for the position.