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Coherence and multimode correlations from vacuum fluctuations in a microwave superconducting cavity
Pasi Lähteenmäki1, Gheorghe Sorin Paraoanu1, Juha Hassel2
1Department of Applied Physics, Low Temperature Laboratory, Aalto University School of Science, PO Box 15100, FI-00076 Aalto, Finland.
Nature Communications
|August 27, 2016
Summary
Researchers demonstrate a novel method to create coherence between photons in separate frequency modes using double parametric pumping in a superconducting microwave cavity. This breakthrough in quantum field theory opens new avenues for quantum information processing.
Area of Science:
- Quantum Field Theory
- Quantum Optics
- Superconducting Circuits
Background:
- Vacuum fluctuations are fundamental to quantum field theory, typically uncorrelated across frequencies.
- Parametric pumping can modulate field parameters, inducing correlations like squeezing.
- Existing methods focus on frequency-symmetric squeezing, not inter-frequency coherence.
Purpose of the Study:
- To investigate the generation of coherence between photons in separate frequency modes.
- To explore the role of double parametric pumping in a superconducting microwave cavity.
- To understand the quantum fluctuation mechanisms driving this novel coherence.
Main Methods:
- Utilizing a superconducting microwave cavity subjected to double parametric pumping.
- Modulating the cavity's Lagrangian parameter with external pumps.
- Analyzing the resulting photon correlations and their tunability.
Main Results:
- Demonstrated the generation of coherence between photons in separate frequency modes.
- Showcased that these coherence correlations are tunable by the phases of the pumps.
- Identified the underlying mechanism as a quantum fluctuation stimulating simultaneous two-photon pair creation.
Conclusions:
- Double parametric pumping enables a new type of vacuum-induced coherence.
- The absence of which-way information in frequency space is key to this phenomenon.
- This finding has potential implications for quantum information processing and fundamental physics.
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