Abstract Body

Currently, the second quantum revolution attracts many researchers’ attention on quantum computing and qubits. As for now, superconducting qubit is supposed to be a most competitive mean for building a multi-qubit universal quantum computer. One of the obstacles in the development of a quantum computer is a short decoherence time. Besides the decoherence in quantum states, breakdown of topological protection, scattering and zero-energy fluctuation are closely involved in detailed and specific dissipation mechanisms. In order to understand and utilize a quantum system or a quantum material, we should figure out how the dissipation works in the system. However, the microscopic energy dissipation is rarely defined and not easy to be measured with enough sensitivity and spatial resolution. The observation of the quantum system requires low-temperature operation, as well.

As a candidate for the potential modalities, I am thinking of a scanning probe nanoscope with a single diamond nitrogen vacancy. The calorimetric sensitivity in our experiment is less than 70 micro-Kelvin per root Hertz. Therefore, we could measure and visualize the dissipation in many interesting systems like superconducting qubits, quantum dot charging, phonon emission due to inelastic electron scattering, protected topological edge current, etc. Here, I introduce the design of our scanning probe nanoscope for the dissipation thermometry.

Acknowledgment

This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (NRF-2021R1A2C2094578: 1711181263).