Method for setting GHZ state generation chip based on quantum frequency comb

Abstract

The invention discloses a method for setting a GHZ state generation chip based on a quantum frequency comb. The chip structurally comprises a quantum frequency comb light source and a path polarization converter, the quantum frequency comb light source comprises 2-3 independent and coherent nonlinear optical parameter conversion units capable of generating frequency comb associated photon pairs and a wavelength division multiplexing unit. The quantum frequency comb light source generates two sets of photon pairs covering all frequencies, the photon pairs are output from an upper path and a lower path respectively, two photons output from each path are paired due to energy conservation in frequency, but the upper path and the lower path correspond to two completely different pairing modes to form two items of a GHZ state, and when only one photon exists in each frequency, a frequency-marked multi-photon path coding GHZ state is obtained; and the path polarization converter transfers thepath information of the photons to the polarization degree of freedom to obtain a multi-photon polarization coding GHZ state.

Description

technical field [0001] The invention relates to the fields of quantum information technology, optical quantum chips and nonlinear optics, and is used for preparing scalable frequency-marked multi-photon GHZ states. Background technique [0002] Quantum entanglement is the core resource in quantum information technologies such as quantum communication and quantum computing. The GHZ state, also known as the "Schrödinger's cat" state [1], is the superposition of states in which all subsystem states are different, such as the three-photon GHZ state: The GHZ state has special properties, and its functions include verification of non-locality [2] and quantum error correction [3], etc. The preparation of multiphoton GHZ states has always been a research difficulty and hotspot in the field of quantum information. At present, many experiments on the preparation of multi-photon GHZ states have been reported, including experiments on bulk optical benches[4-6] and optical quantum chi...

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Problems solved by technology

The number of nonlinear parameter conversion units and other experimental devices required by this type of scheme is large, and as the scale expands, the number of required devices and paths also increases. The number of unit devices is generally on the order of O(n), where n is GHZ The total number of photons in the state, such as the scheme in Reference 6, represents the highest level of bulk optical path design, but the optical path is still relatively complex, and with the increase in the number of photons or path modes, it also needs to occupy more time for quantum state transmission. space channel

That is to say, the traditional method of preparing GHZ state has the disadvantages of complex preparation system and large consumption of space transmission resources, and the traditional preparation method of GHZ state adopts bulk optical path, especially the system involves many discrete nonlinear crystals and optical components, which is even more difficult. Difficult to stabilize and prepare high-quality GHZ state

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