Entanglement of Microwave and Optical Fields Using Electrical Capacitor Loaded With Plasmonic Graphene Waveguide

Abstract

We propose a novel approach for microwave and optical fields entanglement using an electrical capacitor loaded with graphene plasmonic waveguide. In the proposed scheme, a quantum microwave signal of frequency ω m drives the electrical capacitor, while an intensive optical field (optical pump) of frequency ω 1 is launched to the graphene waveguide as surface plasmon polariton (i.e., SPP) mode. The two fields interact by the means of electrically modulating the graphene optical conductivity. It then follows that an upper and lower SPP sideband modes (of ω 2 = ω 1 + ω m and ω 3 = ω 1 − ω m frequencies, respectively) are generated. We have shown that the microwave signal and the lower sideband SPP mode are entangled, given a proper optical pump intensity is provided. A quantum mechanics model is developed to describe the fields evolution. The entanglement of the two fields is evaluated versus many parameters including the waveguide length, the pump intensity, and the microwave frequency. We found that the two fields are entangled over a vast microwave frequency range. Furthermore, our calculations show that a significant number of entangled photons are generated at the lower SPP sideband. The proposed scheme attains tunable mechanism for microwave-optical entanglement which paves the way for efficient quantum systems.

A Local Area Quantum Teleportation Network Based on an Array of Electrically Activated Graphene Waveguide

“…The basic building unit of the proposed system is our previously reported graphene-loaded capacitor [15][16][17], which consists of a graphene plasmonic waveguide integrated with a parallelplate electrical capacitor, as illustrated in Fig 1 . The operating principle of this modality is the cocoupling of two interacting quantum optical fields (for the annihilation operators â2 and â3 and frequencies 𝜔 1 and 𝜔 2 , respectively) that function as counter copropagating surface plasmon polariton (SPP) modes along the graphene layer. A microwave voltage (corresponding to the annihilation operator 𝑏 and frequency 𝜔 𝑚 ) drives the capacitor, enabling the interaction process by electrically perturbing the graphene conductivity [18,19].…”

Continuous-Variable Quantum Teleportation Using Microwave Enabled Plasmonic Graphene Waveguide

“…is the speed of light, and Z 0 represents the free space impedance. The graphene conductivity ζ is given by [23,33]:…”

“…However, the entanglement of the microwave and optical photons using mechanical resonators is very sensitive to the thermal noise. In earlier works [26,28,33], two authors of our group have proposed a scheme for an efficient low noise conversion of quantum electrical signal to optical signal and vice versa by using many layers of graphene. It has been seen that a few microvolts driving quantum microwave signal can be efficiently converted to the optical frequency domain by exploiting several graphene layers.…”

“…Two-mode squeezed light is the primary resource for quantum information and quantum communication with continuous variable systems [29][30][31][32]. A hybrid two-mode squeezing of microwave and optical fields has also been recently proposed by our group using a plasmonic grapheneloaded capacitor [33]. In this paper, we present a scheme to realize continuous variable (i.e., CV) entangled states between two different radiations at different wavelengths by using a superconducting electrical capacitor which is loaded with graphene plasmonic waveguide and driven by a microwave quantum signal.…”

Hybrid two-mode squeezing of microwave and optical fields using optically pumped graphene layers

“…Achieving a hybrid two-mode squeezing paves the way towards merging the superconducting quantum systems with photonics systems. It then ultimately leads to hybrid systems that leverage the advantages of both 29 . Furthermore, the advantages of our proposed squeezing scheme include its simple structure (with no phase matching or SQUID insertion required), moderate cryogenic operation temperature, and tunability over a vast microwave frequency range.…”