Engineering Faculty, Electrical and Electronic Department, Cankaya University, Ankara, Turkey.
Sci Rep. 2023 Jul 17;13(1):11528. doi: 10.1038/s41598-023-37739-0.
This study significantly concentrates on cryogenic InP HEMT high-frequency circuit analysis using quantum theory to find how the transistor nonlinearity can affect the quantum correlation of the modes generated. Firstly, the total Hamiltonian of the circuit is derived, and the dynamic equation of the motion contributed is examined using the Heisenberg-Langevin equation. Using the nonlinear Hamiltonian, some components are attached to the intrinsic internal circuit of InP HEMT to address the circuit characteristics fully. The components attached are arisen due to the nonlinearity effects. As a result, the theoretical calculations show that the states generated in the circuit are mixed, and no pure state is produced. Accordingly, the modified circuit generates the two-mode squeezed thermal state, which means one can focus on calculating the Gaussian quantum discord to evaluate quantum correlation. It is also found that the nonlinearity factors (addressed as the nonlinear components in the circuit) can intensely influence the squeezed thermal state by which the quantum discord is changed. Finally, as the primary point, it is concluded that although it is possible to enhance the quantum correlation between modes by engineering the nonlinear components; however, attaining quantum discord greater than unity, entangled microwave photons, seems a challenging task since InP HEMT operates at 4.2 K.
本研究主要集中在使用量子理论对低温磷化铟高电子迁移率晶体管高频电路进行分析，以研究晶体管的非线性如何影响产生的模式的量子相关性。首先，导出了电路的总哈密顿量，并使用海森堡-朗之万方程研究了运动的动力学方程。使用非线性哈密顿量，将一些分量附加到磷化铟高电子迁移率晶体管的固有内部电路中，以充分解决电路特性。所附加的分量是由于非线性效应引起的。结果表明，理论计算表明电路中产生的状态是混合的，不会产生纯态。因此，修改后的电路产生了双模压缩热态，这意味着可以集中计算高斯量子离差来评估量子相关性。还发现，非线性因素（在电路中表示为非线性分量）可以通过改变量子离差来强烈影响压缩热态。最后，作为主要观点，得出的结论是，尽管通过工程设计非线性分量可以增强模式之间的量子相关性；然而，由于磷化铟高电子迁移率晶体管在 4.2 K 下工作，因此似乎很难实现大于单位的量子离差，从而产生纠缠微波光子。
