Controlling dephasing of coupled qubits via shared-bath coherence (2405.14685v2)
Abstract: The interaction of a quantum system with its environment limits its coherence time. This, in particular, restricts the utility of qubits in quantum information processing applications. In this paper, we show that the decoherence of a coupled qubit system can be minimized, or even eliminated, by exploiting the quantum coherence of the bath itself. We investigate the dephasing in a system of two spatially separated, electronically decoupled qubits, with direct or mediated coupling, interacting with a shared bath. For illustration, we treat F\"orster or cavity-mediated coupling between semiconductor quantum dots interacting with acoustic phonons. Using the rigorous method of Trotter's decomposition with cumulant expansion, we demonstrate a reduction in the dephasing rates at specific distances between the dots. The control of dephasing with distance is a coherent effect of the shared bath and is absent for independent baths. It can be understood in terms of phonon-assisted transitions between the entangled qubit states of the coupled system.
- C. Monroe, Quantum information processing with atoms and photons, Nature 416, 238 (2002).
- M. Schlosshauer, Quantum decoherence, Physics Reports 831, 1 (2019).
- P. Zanardi and M. Rasetti, Noiseless quantum codes, Phys. Rev. Lett. 79, 3306 (1997).
- D. A. Lidar, I. L. Chuang, and K. B. Whaley, Decoherence-free subspaces for quantum computation, Phys. Rev. Lett. 81, 2594 (1998).
- B. Krummheuer, V. M. Axt, and T. Kuhn, Theory of pure dephasing and the resulting absorption line shape in semiconductor quantum dots, Phys. Rev. B 65, 195313 (2002).
- E. A. Muljarov and R. Zimmermann, Dephasing in Quantum Dots: Quadratic Coupling to Acoustic Phonons, Phys. Rev. Lett. 93, 237401 (2004).
- E. A. Muljarov, T. Takagahara, and R. Zimmermann, Phonon-induced exciton dephasing in quantum dot molecules, Phys. Rev. Lett. 95, 177405 (2005).
- M. Glässl, A. M. Barth, and V. M. Axt, Proposed robust and high-fidelity preparation of excitons and biexcitons in semiconductor quantum dots making active use of phonons, Phys. Rev. Lett. 110, 147401 (2013).
- A. Morreau, C. Joshi, and E. A. Muljarov, Phonon-induced dephasing in quantum dot-cavity QED: Limitations of the polaron master equation, arXiv:2002.01912 .
- L. S. Sirkina and E. A. Muljarov, Impact of the phonon environment on the nonlinear quantum-dot–cavity qed: Path-integral approach, Phys. Rev. B 108, 115312 (2023).
- I. Wilson-Rae and A. Imamoglu, Quantum Dot Cavity-QED in the Presence of Strong Electron-Phonon Interactions, Phys. Rev. B 65, 235311 (2002) .
- A. Morreau and E. A. Muljarov, Phonon-induced dephasing in quantum-dot–cavity QED, Phys. Rev. B 100, 115309 (2019).
- A. O. Govorov, Spin-Förster transfer in optically excited quantum dots, Phys. Rev. B 71, 155323 (2005).
- E. Rozbicki and P. Machnikowski, Quantum Kinetic Theory of Phonon-Assisted Excitation Transfer in Quantum Dot Molecules, Phys. Rev. Lett. 100, 027401 (2008).
- A. Thilagam and M. A. Lohe, Decoherence of excitonic qubits in Förster coupled quantum dots, J. Phys.: Condens. Matter 20, 315205 (2008).
Paper Prompts
Sign up for free to create and run prompts on this paper using GPT-5.
Top Community Prompts
Collections
Sign up for free to add this paper to one or more collections.
