At a low temperature, nearly macroscopic quantum states can be sustained in superconducting (SC) Josephson junctions. Recently, these superconducting qubits have been coupled to electromagnetic resonators, in a manner analogous to cavity Quantum Electro Dynamics (QED) which describes the interaction between atoms and quantized oscillation modes in the quantum limit. On the other hand, there is yet no experimental evidence of a mode of a mechanical oscillator, such as that of a miniaturized vibrating string, to be chilled down to its quantum ground state. The main part of the proposal involves the use the coupling of Nanomechanical Resonators (NR) to SC qubits employed as artificial atoms in order to address the quantum-classical interface in mechanical motion. Similarly as the SC qubit can exchange quanta with electrical oscillators, it can, in principle, communicate with mechanical modes. The research will begin with demonstrating this kind of electromechanical interaction. In order to tackle experimental surprises, I plan on launching two parallel paths, one with a charge qubit, the other using a phase qubit. The formidable main goal is to experimentally reach the quantum ground state of a mechanical mode. I will investigate the following routes: Make a 1 GHz frequency NR, corresponding to 50 mK, which will reach the ground state at accessible temperatures. On the other hand, I propose to side-band cool a lower-frequency NR via the attached SC qubit. Near the quantum limit, I will start taking advantage of the NR as a building block of electromechanical quantum information. I also propose to push the QED setup of SC qubits coupled to electrical cavities towards more and more complicated states in order to test quantum mechanics in the nearly classical limit.
Field of science
- /engineering and technology/electrical engineering, electronic engineering, information engineering/electronic engineering/computer hardware/quantum computer
- /natural sciences/physical sciences/quantum physics
- /natural sciences/physical sciences/electromagnetism and electronics/electrical conductivity/superconductor
Call for proposal
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