Quantum correlation of microwave two-mode squeezed state generated by nonlinearity of InP HEMT

Area of Science:

• Quantum physics and condensed matter physics.
• High-frequency electronic circuit analysis.

Background:

• Investigating quantum correlations in electronic circuits is crucial for quantum information processing.
• Indium Phosphide High Electron Mobility Transistors (InP HEMTs) are key components in high-frequency applications.

Purpose of the Study:

• To analyze cryogenic InP HEMT high-frequency circuits using quantum theory.
• To determine how transistor nonlinearity affects quantum correlation of generated modes.
• To explore the generation of non-pure quantum states and their properties.

Main Methods:

• Derivation of the total Hamiltonian for the InP HEMT circuit.
• Examination of dynamic equations of motion using the Heisenberg-Langevin equation.
• Incorporation of nonlinear components into the circuit model to represent nonlinearity effects.

Main Results:

• Theoretical calculations revealed that generated states are mixed, not pure.
• The modified circuit generates a two-mode squeezed thermal state.
• Nonlinearity factors significantly influence the squeezed thermal state and alter quantum discord.

Conclusions:

• Quantum correlation between modes can be enhanced by engineering nonlinear components.
• Achieving quantum discord greater than unity (entangled microwave photons) is challenging at 4.2 K.
• The study provides insights into quantum correlations in cryogenic InP HEMT circuits.