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Generation of GKP states with optical states



Scott C. Glancy, Hilma M. Vasconcelos, Liliana Sanz


Classical information can be carried by either a discrete signal or by a continuous signal. Quantum information can also be carried by a discrete, finite-dimensional system, such as a two-level atom or an electron spin, or by continuous, infinite dimensional system, such as a harmonic oscillator. In Gottesman et al. [1] a qubit is encoded in the continuous position and momentum degrees of freedom of an oscillator (Gottesman - Kitaev - Preskill or GKP qubit states). One likely realization of GKP states is in the quadrature variables of traveling light waves. Quantum computation can be performed on GKP states using relatively simple linear optical devices, squeezing, and homodyne detection. However, the initial GKP states are extremely difficult to prepare. Here we propose the generation of an approximate GKP state by using superpositions of optical coherent states (sometimes called Schr dinger cat states ), linear optical devices, squeezing, and homodyne detection. We initially consider two optical modes containing Schr dinger cat states. A displacement followed by a squeezing is applied to both modes and then the two modes are sent into a beam splitter. The action of the beam splitter entangles the two modes. An approximate GKP state is obtained when we perform a measurement of the p-quadrature in one of the beam splitter output modes.
Proceedings Title
XXXII Brazilian Meeting on Condensed Matter Physics
Conference Dates
May 11-15, 2009
Conference Location
Águas de Lindóia


coherent states, linear optical quantum computer


Glancy, S. , Vasconcelos, H. and Sanz, L. (2009), Generation of GKP states with optical states, XXXII Brazilian Meeting on Condensed Matter Physics, Águas de Lindóia, -1, [online], (Accessed April 22, 2024)
Created May 11, 2009, Updated February 19, 2017