Postdoctoral Researcher

The Quantum Nanomechanics group at the Department of Applied Physics, is seeking outstanding candidates for the position of Postdoctoral Researcher to conduct experimental research in projects related to quantum micromechanical systems. Our team investigates how mechanical oscillators can be utilized for fundamental studies probing quantum mechanics in massive systems, as well as for applications in quantum information processing. The measurements are carried out at deep cryogenic temperatures in dilution refrigerators. Notably, we have demonstrated quantum entanglement between two micromechanical oscillators realized as vibrating aluminum drumheads [Nature 556, 478 (2018)], [Science 372, 625 (2021)].

Project 1: Gravitational coupling between nonclassical masses

This project aims to address one of the great unresolved challenges in physics: While quantum mechanics successfully describes low-energy phenomena, it is incompatible with general relativity which governs gravity and huge energies. The interface between these two has remained experimentally elusive, because only the most violent events in the universe have been considered to produce measurable effects due to the plausible quantum behavior of gravity. We aim at detecting gravitational forces for the first time within a quantum system. We use mechanical oscillators loaded by milligram masses and bring two such gravitationally interacting oscillators into nonclassical motional states. The initial phase of the project focuses on measuring the gravitational force between milligram-scale gold particles, representing a new mass scale showing gravitational forces within a system. This work is part of the ERC Advanced Grant project “GUANTUM: Probing the limits of quantum mechanics and gravity with micromechanical oscillators”.

Project 2: Remote connection and strong coupling in coherent electromechanics

We utilize “microwave optomechanical” devices, where micromechanical membrane oscillators interact with on-chip microwave cavity resonators. Optomechanical techniques allow for both preparing, measuring and manipulation of the mechanical quantum states. So far, true quantum states in such systems have been reached in only in physically adjacent components. We aim to extend this to remotely connected electromechanical systems capable of sharing a quantum state. This opens possibilities for fundamental studies in remote entanglement and quantum teleportation of mechanical states, as well as ultra-sensitive detection of weak, long-range forces—such as those predicted by physics beyond the Standard Model. Distant, coupled microwave optomechanical systems can also be utilized for quantum information transmission. In this project, two electromechanical quantum chips are connected via superconducting cables at millikelvin temperatures. The vibrating membranes will be realized with a phononic crystal radiation shield, enabling ultrahigh mechanical quality factors. In the project we are also interested in increasing the electromechanical coupling by creating a nanometer-size vacuum gap connection to the vibrating membrane via nanopositioning. This work is part of European Union’s Quantera Program project “MQSens: Quantum Sensing with Nonclassical Mechanical Oscillators”, where opto-/electromechanics is utilized to explore how quantum protocols can be adapted to mechanical sensors in the quantum regime for various applications.

Your role

The experimental work in all these projects involves design of the samples and of the measurement setups, cleanroom fabrication, performing cryogenic microwave measurements, and data analysis. You are expected to participate in advising and mentoring PhD students.

Your experience and ambitions

For this challenging research, we are looking for brilliant and energetic individuals who are motivated in experimental, low-temperature quantum physics. We require the candidates to have a proven track record in experimental research with similar or related topics, cleanroom microfabrication, and strong interest in micromechanical systems. Additionally, the candidates should be excellent team players. Experience with cryogenics and dilution refrigerators, and skill in theoretical understanding of the studied phenomena, are considered significant assets.

We require the candidates to have excellent skills in English. Finnish language is not required. To be eligible, a postdoctoral researcher must hold a PhD degree in a suitable field.

What we offer

The Quantum Nanomechanics team, ambitous but relaxed with a great team spirit, conducts cutting-edge experimental research on the foundations of quantum mechanics. With superconducting qubits, we explore processing of quantum information with mechanical motion. In our more applied research, we lay the foundation for a new generation of devices that use various types of microwave-optomechanical effects for efficient signal processing. We have realized quantum-limited microwave amplifiers and nonreciprocal components to be used in superconducting quantum technology.

The fixed term contract is typically initially for two years and can be extended on mutual agreement. Aalto University follows the salary system of Finnish universities. The starting salary for a Postdoctoral researcher is approx. 4130 €/month. The salary ranges from 4130 € to 4550 € per month, depending on previous experience. The contract includes occupational healthcare.

The workplace will be the Otaniemi Campus of Aalto University, in the premises of the OtaNano national research infrastructure for micro- and nanotechnologies. OtaNano provides access to all the advanced nanofabrication, nanomicroscopy and measurement facilities and techniques. VTT Technical Research Centre of Finland on campus leverages the bridge between research and innovation. Several startup companies working with electronics, cryogenics, and quantum technology have recently emerged in the community. Our team belongs to the Finnish Quantum Flagship national initiative that is harnessing quantum phenomena for solid-state-based quantum devices and applications.