### Abstract

Original language | English |
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Title of host publication | Proceedings |

Subtitle of host publication | Progress in Electromagnetics Research Symposium, PIERS 2013 |

Publisher | Electromagnetics Academy |

Pages | 151-153 |

ISBN (Print) | 978-193414224-0 |

Publication status | Published - 2013 |

MoE publication type | Not Eligible |

Event | 33rd Progress in Electromagnetics Research Symposium, PIERS 2013 - Taipei, Taiwan, Province of China Duration: 25 Mar 2013 → 28 Mar 2013 Conference number: 33 |

### Conference

Conference | 33rd Progress in Electromagnetics Research Symposium, PIERS 2013 |
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Abbreviated title | PIERS 2013 |

Country | Taiwan, Province of China |

City | Taipei |

Period | 25/03/13 → 28/03/13 |

### Fingerprint

### Cite this

*Proceedings: Progress in Electromagnetics Research Symposium, PIERS 2013*(pp. 151-153). Electromagnetics Academy.

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*Proceedings: Progress in Electromagnetics Research Symposium, PIERS 2013.*Electromagnetics Academy, pp. 151-153, 33rd Progress in Electromagnetics Research Symposium, PIERS 2013, Taipei, Taiwan, Province of China, 25/03/13.

**Photon generation from quantum vacuum using a josephson metamaterial.** / Lähteenmäki, P.; Paraoanu, G.S.; Hassel, Juha; Hakonen, P.

Research output: Chapter in Book/Report/Conference proceeding › Conference article in proceedings › Scientific › peer-review

TY - GEN

T1 - Photon generation from quantum vacuum using a josephson metamaterial

AU - Lähteenmäki, P.

AU - Paraoanu, G.S.

AU - Hassel, Juha

AU - Hakonen, P.

PY - 2013

Y1 - 2013

N2 - When one of the parameters in the Euler-Lagrange equations of motion of a sys- tem is modulated, particles can be generated out of the quantum vacuum. This phenomenon is known as the dynamical Casimir effect, and it was recently realized experimentally in systems of superconducting circuits, for example by using modulated resonators made of coplanar waveg- uides, or arrays of superconducting quantum intereference devices (SQUIDs) forming a Josephson metamaterial. In this paper, we consider a simple electrical circuit model for dynamical Casimir effects, consisting of an LC resonator, with the inductor modulated externally at 10.8 GHz and with the resonant frequency tunable over a range of ±400MHz around 5.4 GHz. The circuit is analyzed classically using a circuit simulator (APLAC). We demonstrate that if an additional source of classical noise couples to the resonator (on top of the quantum vacuum), for example via dissipative "internal modes", then the resulting spectrum of the photons in the cavity will present two strongly asymmetric branches. However, according to the theory of the dynamical Casimir effect, these branches should be symmetric, a prediction which is confirmed by our ex- perimental data. The simulation presented here therefore shows that the origin of the photons generated in our experiment with Josephson metamaterials is the quantum vacuum, and not a spurious classical noise source.

AB - When one of the parameters in the Euler-Lagrange equations of motion of a sys- tem is modulated, particles can be generated out of the quantum vacuum. This phenomenon is known as the dynamical Casimir effect, and it was recently realized experimentally in systems of superconducting circuits, for example by using modulated resonators made of coplanar waveg- uides, or arrays of superconducting quantum intereference devices (SQUIDs) forming a Josephson metamaterial. In this paper, we consider a simple electrical circuit model for dynamical Casimir effects, consisting of an LC resonator, with the inductor modulated externally at 10.8 GHz and with the resonant frequency tunable over a range of ±400MHz around 5.4 GHz. The circuit is analyzed classically using a circuit simulator (APLAC). We demonstrate that if an additional source of classical noise couples to the resonator (on top of the quantum vacuum), for example via dissipative "internal modes", then the resulting spectrum of the photons in the cavity will present two strongly asymmetric branches. However, according to the theory of the dynamical Casimir effect, these branches should be symmetric, a prediction which is confirmed by our ex- perimental data. The simulation presented here therefore shows that the origin of the photons generated in our experiment with Josephson metamaterials is the quantum vacuum, and not a spurious classical noise source.

M3 - Conference article in proceedings

SN - 978-193414224-0

SP - 151

EP - 153

BT - Proceedings

PB - Electromagnetics Academy

ER -