Two-photon interference of the emission from electrically tunable remote quantum dots

• Published in: Nature photonics Vol. 4; no. 9; pp. 632 - 635
• Main Authors: Patel, Raj B, Bennett, Anthony J, Farrer, Ian, Nicoll, Christine A, Ritchie, David A, Shields, Andrew J
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01-09-2010; Nature Publishing Group
• Subjects: 639/624/1075/187; 639/624/1075/401; 639/624/399/1017; 639/624/400/1021; Applied and Technical Physics; Classical and quantum physics: mechanics and fields; Devices; Electric fields; Emission; Emissions; Encoding; Exact sciences and technology; Interference; letter; Oscillations; Physics; Physics and Astronomy; Quantum dots; Quantum information; Quantum Physics; Qubits (quantum computing); Self-assembly; Energy levels; Quantum dots; Electric field effects; Single atom; Quantum optics; Encoding; Quantum information; Quantum interference phenomena
• ISSN: 1749-4885; 1749-4893
• DOI: 10.1038/nphoton.2010.161

Self-assembled quantum dots comprise a versatile system with which to study quantum effects in the solid state. Many devices have been developed that demonstrate controlled charging of a quantum dot
1
, Rabi oscillations
2
, coherent spin control
3
and electrically injected non-classical photon emission
4
. Often referred to as ‘artificial atoms’, quantum dots have discrete energy levels, making them a viable candidate for encoding qubits. However, unlike single atoms, no two quantum dots are alike. This is a complication for quantum-information applications that require qubits initialized in the same state and interactions between remote systems mediated by indistinguishable photons. We report that truly remote, independent, quantum dots can be tuned to the same energy using large applied electric fields. This allows two-photon interference
5
of their emission under coincidence gating and opens up the possibility of transferring quantum information between remote solid-state sources.
Truly remote, independent InGaAs quantum dots are tuned to the same energy using large applied electric fields of up to −500 kV cm
−1
. This allows for two-photon interference of their emission under coincidence gating, and opens up the possibility of transferring quantum information between remote solid-state sources.