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Resonance Fluorescence of an InGaAs Quantum Dot in a Planar Cavity Using Orthogonal Excitation and Detection
Published on: October 13, 2017
Cavity QED with magnetically coupled collective spin states.
R Amsüss1, Ch Koller, T Nöbauer
1Vienna Center for Quantum Science and Technology, Atominstitut, TU Wien, Austria.
Physical Review Letters
|September 10, 2011
Summary
We achieved strong coupling between nitrogen-vacancy (NV) electron spins in diamond and a superconducting resonator. This demonstrates a key step towards building quantum memories using nuclear spins and NV centers.
Area of Science:
- Quantum computing
- Solid-state physics
- Diamond quantum technologies
Background:
- Nitrogen-vacancy (NV) centers in diamond are promising solid-state qubits.
- Superconducting resonators are essential components in quantum circuits.
- Strong coupling between qubits and resonators is crucial for quantum information processing.
Purpose of the Study:
- To demonstrate strong coupling between an ensemble of NV center electron spins and a superconducting microwave resonator.
- To investigate the scaling of collective coupling strength with the number of NV centers.
- To explore the potential for NV centers as quantum memories via hyperfine coupling to nuclear spins.
- To measure NV center relaxation times nondestructively at millikelvin temperatures.
Main Methods:
- Ensemble of nitrogen-vacancy (NV) electron spins in diamond.
- Superconducting microwave coplanar waveguide resonator.
- Measurement of collective coupling strength and its dependence on the number of emitters.
- Measurement of hyperfine coupling to carbon-13 (13C) nuclear spins.
- Nondestructive measurement of NV center relaxation time using cavity resonance frequency shifts at millikelvin temperatures.
Main Results:
- Achieved strong coupling between NV electron spins and the superconducting resonator.
- Observed the characteristic square-root scaling of collective coupling strength with the number of NV centers.
- Measured hyperfine coupling to 13C nuclear spins, indicating potential for nuclear quantum memory.
- Nondestructively measured NV center relaxation time at millikelvin temperatures.
Conclusions:
- Strong coupling between NV electron spins and superconducting resonators is experimentally verified.
- The observed scaling provides direct evidence of collective effects in the spin ensemble.
- The hyperfine coupling measurement is a significant step towards developing nuclear ensemble quantum memories.
- Nondestructive relaxation time measurements at low temperatures are feasible, crucial for quantum device characterization.
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