Research assistant on Experimental Control of Rydberg Ions

Department of Physics at Stockholm University is one of the largest departments within the Faculty of Science and supports a broad range of basic research in experimental and theoretical physics. It has about 250 employees, of which 95 are PhD students. Many have been internationally recruited. The Department is part of the AlbaNova University Center, which apart from the Department of Physics houses the Department of Astronomy, the Physics Departments at the Royal Institute of Technology (KTH), and the Nordic Institute for Theoretical Physics (Nordita). You can read more about us here: Department of Physics.

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Main responsibilities

We offer a full-time paid summer internship for an undergraduate student in the Trapped Ion Quantum Technologies Group. The research assistant will participate in optimising a new experiment aimed at trapping Rydberg ions in cryogenic temperatures.

Trapped ions excited to Rydberg states offer fast interaction between their electronic states via dipole-dipole interaction. In quantum information processing, this interaction enables multi-qubit gates that could be much faster than conventional gates based on motional interaction. Time spent in the Rydberg state is, however, limited by surrounding black-body radiation that causes double ionisation. For this reason, we are developing an ion trap set in a cryogenic chamber, which will prolong the lifetime of Rydberg states and enable more complex quantum protocols.

Reliable laser control of the ions' electronic states is crucial for all measurements. An ultra-narrow-linewidth laser at 674 nm is used for coherent control of two long-lived qubit states, and its phase stability and bandwidth need to be optimised. Additionally, two UV lasers will be delivered from the next lab for two-photon transition to the Rydberg state, which poses a challenge of pointing stability and power efficiency. And finally, to keep the ions within the focus point of the laser beams, mechanical vibrations of the cryostat need to be minimised.

The applicant will take responsibility for optimising one or more aspects of the experiment. For the narrow-linewidth qubit laser, we intend to implement self-injection locking and feedforward filtering. The UV lasers will be delivered via a free-space bridge, and so careful beam shaping, steering, and loss budgeting will be necessary. Mechanical vibrations can be suppressed by designing and deploying a heavy bellow holder placed between the cryostat and the Gifford-McMahon cold head.

The summer internship project will take place in the Trapped Ion Quantum Technology group at Stockholm University headed by Prof. Markus Hennrich, and is financed by the Marianne and Marcus Wallenberg’s foundation (EDU-WACQT). For more information see http://qtech.fysik.su.se/.

Qualification requirements

• Ongoing undergraduate studies in a field related to physics or optics, with expected graduation no sooner than the end of the internship
• Good English communication skills
• Interest in experimental work.

About the employment

The is a full-time, intended for 11 weeks during summer. The time frame can be adjusted per the applicant's academic schedule. Stockholm University applies individual salary setting. Start date as agreement.

We offer

With us, you will experience the dynamic interaction between higher education and research that makes Stockholm University an exciting and creative environment. You will work in an international environment and get favourable conditions. The university is located in the National City Park with good transport links to the city.

Stockholm University strives to be a workplace free from discrimination and with equal opportunities for all.

Contact

Further information about the position can be obtained from Ivo Straka, phone: +46 8 5537 8088, ivo.straka@fysik.su.se.

Application

Apply for the position at Stockholm University's recruitment system. It is the responsibility of the applicant to ensure that the application is complete and that it is submitted before the deadline.

The instructions for applicants are available at: How to apply for a position.