Entropy flow in CR-gate

Cross-resonance gate is a two-qubit gate performed by driving one of the qubits (control) at the frequency of the other (target) [1]. We study such a sytem in the presence of external reservoirs [2]. In our model each qubit is coupled to a reservoir, where each reservoir is at a different temperature. The qubits also interact with each other and hence evolve to become entangled [3]. We calculate the entropy flow through the reservoirs and see how it is affected by the entanglement between the qubits [4]. Obtaining such a relation makes it feasible to control the entropy flow within a system by controlling the entanglement between qubits.

[1] G. S. Paraoanu, Microwave-induced coupling of superconducting qubits, Phys. Rev. B 74, 140504(R) (2006), arXiv:0801.4541

[2] Mohammad H. Ansari, Yuli V. Nazarov, Rényi entropy flows from quantum heat engines, Phys. Rev. B 91, 104303 (2015), arXiv:1408.3910

[3] Jerry M. Chow, A. D. Córcoles, Jay M. Gambetta, Chad Rigetti, B. R. Johnson, John A. Smolin, J. R. Rozen, George A. Keefe, Mary B. Rothwell, Mark B. Ketchen, and M. Steffen, Simple All-Microwave Entangling Gate for Fixed-Frequency Superconducting Qubits, Phys. Rev. Lett. 107, 080502 (2011)

[4] Mohammad H. Ansari, Alwin van Steensel, Yuli V. Nazarov, Entropy Production in Quantum Is Different, Entropy 2019, 21(9), 854 (2019), arXiv:1907.09241