Observation of Broadband Entanglement in Microwave Radiation from a Single Time-Varying Boundary Condition
Journal article, 2020

Entangled pairs of microwave photons are commonly produced in the narrow frequency band of a resonator, which represents a modified vacuum density of states. We generate and investigate the entanglement of a stream of photon pairs, generated in a semi-infinite broadband transmission line, terminated by a superconducting quantum interference device (SQUID). A weak pump signal modulates the SQUID inductance, resulting in a single time-varying boundary condition, and we detect all four quadratures of the microwave radiation emitted at two different frequencies separated by 0.7 GHz. Power calibration is done in situ, and we find positive logarithmic negativity and two-mode squeezing below the vacuum in the observed radiation, indicating entanglement.

Boundary conditions

Microwave resonators

SQUIDs

Quantum interference devices

Molluscs

Photons

Author

Ben Schneider

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Technology

Andreas Bengtsson

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Technology

Ida-Maria Svensson

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Technology

Thomas Aref

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics

Göran Johansson

Chalmers, Microtechnology and Nanoscience (MC2), Applied Quantum Physics

Jonas Bylander

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Technology

Per Delsing

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Technology

Physical Review Letters

0031-9007 (ISSN) 1079-7114 (eISSN)

Vol. 124 14 140503

Quantum states of photons and relativistic physics on a chip

Knut and Alice Wallenberg Foundation, 2015-01-01 -- 2019-12-31.

Areas of Advance

Nanoscience and Nanotechnology (2010-2017)

Subject Categories

Nano Technology

Condensed Matter Physics

DOI

10.1103/PhysRevLett.124.140503

PubMed

32338986

More information

Latest update

6/26/2020