TY  - JOUR
AU  - Zakka-Bajjani, Eva
AU  - Nguyen, Franà ois
AU  - Lee, Minhyea
AU  - Vale, Leila R.
AU  - Simmonds, Raymond W.
AU  - Aumentado, José
PY  - 2011
DA  - 2011//
TI  - Quantum superposition of a single microwave photon in two different 'colour' states
T2  - Nat. Phys.
JO  - Nature Physics
SP  - 599
EP  - 603
VL  - 7
IS  - 8
KW  - fromIPMRAS
AB  - Fully controlled coherent coupling of arbitrary harmonic oscillators is an important tool for processing quantum information. Coupling between quantum harmonic oscillators has previously been demonstrated in several physical systems using a two-level system as a mediating element. Direct interaction at the quantum level has only recently been realized by means of resonant coupling between trapped ions. Here we implement a tunable direct coupling between the microwave harmonics of a superconducting resonator by means of parametric frequency conversion. We accomplish this by coupling the mode currents of two harmonics through a superconducting quantum interference device (SQUID) and modulating its flux at the difference (~7GHz) of the harmonic frequencies. We deterministically prepare a single-photon Fock state and coherently manipulate it between multiple modes, effectively controlling it in a superposition of two different 'colours'. This parametric interaction can be described as a beamsplitter-like operation that couples different frequency modes. As such, it could be used to implement linear optical quantum computing protocols on-chip.
N1  - exported from refbase (https://db.rplab.ru/refbase/show.php?record=822), last updated on Sat, 12 May 2012 14:59:40 -0500
ID  - Zakka-Bajjani_etal2011
ER  -