Final Report Summary - NEMSQED (Electromechanical quantum coherent systems)
When considering tiny constituents of matter, such as single atoms or molecules, the laws of nature seem to contradict common sense. Atoms or small elementary particles can properly be understood only by quantum physics. Since everything is built with atoms, in principle also macroscopic sized objects follow the counterintuitive quantum laws. If well protected from noise from the surroundings, tangible objects can retain some quantum features. In the NEMSQED project we use nanomechanical oscillators, measuring only a tenth of a diameter of hair, but huge at atomic scale. We operate them at a very low temperature near the absolute zero at -273 C. Under these conditions, their motion can show features explained only by quantum mechanics.
We device the nanomechanical oscillators inside superconducting cavity resonators. When these two systems are put together, they begin exchange quanta. We can operate the system so that their resonant motion becomes amplified. This way, we show how a nanomechanical oscillator can be applied in order to detect or amplify feeble radio waves or microwaves, having direct technological relevance. On the other hand, the resonant motion can become damped which allows for approaching the quantum-mechanical lowest energy state. We have proven this for multimode superconducting systems, as well as for graphene resonators. The setup provides a flexible platform for creation and studies of nonclassical motional states entangled over the chip, or over macroscopic distances. For more applied point of view, the setup is easily extended to embody nearly arbitrarily many mechanical resonators, hence allowing for designing an electromechanical metamaterial with microwave-tunable properties.
Quantum systems with different types of degrees of freedom can inter-twine, forming hybrid entangled quantum states with intriguing properties, such as collective excitations of light and lattice vibrations in semiconductors. We have merged three quantum systems: a superconducting qubit is interacting with two different resonant cavities. A low frequency phonon cavity was used as a storage of quantum information from the qubit, whereas an electrical microwave resonator acted as a means of communicating to the outside world. On the other hand, one can use a similar system in order to enhance the optomechanical interaction energy.
We device the nanomechanical oscillators inside superconducting cavity resonators. When these two systems are put together, they begin exchange quanta. We can operate the system so that their resonant motion becomes amplified. This way, we show how a nanomechanical oscillator can be applied in order to detect or amplify feeble radio waves or microwaves, having direct technological relevance. On the other hand, the resonant motion can become damped which allows for approaching the quantum-mechanical lowest energy state. We have proven this for multimode superconducting systems, as well as for graphene resonators. The setup provides a flexible platform for creation and studies of nonclassical motional states entangled over the chip, or over macroscopic distances. For more applied point of view, the setup is easily extended to embody nearly arbitrarily many mechanical resonators, hence allowing for designing an electromechanical metamaterial with microwave-tunable properties.
Quantum systems with different types of degrees of freedom can inter-twine, forming hybrid entangled quantum states with intriguing properties, such as collective excitations of light and lattice vibrations in semiconductors. We have merged three quantum systems: a superconducting qubit is interacting with two different resonant cavities. A low frequency phonon cavity was used as a storage of quantum information from the qubit, whereas an electrical microwave resonator acted as a means of communicating to the outside world. On the other hand, one can use a similar system in order to enhance the optomechanical interaction energy.