MechQSim · A nano-electromechanical quantum simulator

Electron-phonon interactions lead to a plethora of phenomena in strongly correlated solid-state systems such as superconductivity and charge-density waves. However, the complex dynamics manifesting these phases can be beyond the reach of computational modelling, especially when taking into account electron-electron interaction. Therefore, one of the outstanding challenges in the field of correlated-electron physics is a widely tuneable model system that can mutually couple several electronic and phononic degrees of freedom. To date, no such system has been experimentally realized. While previous efforts have mostly focused on cold-atom configurations, nano-electromechanical systems are naturally suited to address this challenge. One of the most challenging requirements to engineering such a system is the achievement of ultrastrong electromechanical coupling, which has been recently demonstrated for the first time in a capacitively coupled carbon nanotube. Leveraging this capability, we propose to engineer a model system in which electronic degrees of freedom are defined within four quantum dots and coupled to vibrational modes of a carbon nanotube. If successful, the project will enable the first experimental platform for quantum simulation of electron-phonon coupling. The proposal combines techniques from different fields to create a hybrid quantum system that significantly extends the state-of-the-art in nano-electromechanics. The Quantum NanoElectronics & NanoMechanics group at ICFO is one of the two only research groups to experimentally demonstrate ultrastrong electromechanical coupling to date and is the world leader in the fabrication of ultraclean carbon nanotubes. These capabilities, combined with my strong background in both experimental and theoretical nanomechanics, place us in a unique position to realize this milestone.