Realizing highly entangled states in asymmetrically coupled three NV centers at room temperature

TL;DR

This paper demonstrates strong entanglement among three NV centers at room temperature using simulated quantum gates, achieving significantly improved entanglement times and fidelity in disordered configurations.

Contribution

It introduces a novel simulation approach for entangling three NV centers with asymmetric couplings, showing enhanced entanglement times and fidelity at room temperature.

Findings

Achieved entanglement time 2t_ent ~12.5 μs in symmetric configuration.

Reduced entanglement time to 6.3 μs by breaking symmetry.

Demonstrated high fidelity (0.89-0.99) in disordered NV center configurations.

Abstract

Despite numerous efforts the coupling between randomly arranged multi-NV centers and also resonators has not been improved significantly mainly due to our limited knowledge of their entanglement times (2t_ent). Here, we demonstrate a very strong coupling between three-NV centers by using a simulated triple electron-electron resonance experiment based on a new quantum (U_C) gate on IBM quantum simulator with 2t_ent ~12.5 microsecond arranged is a triangular configuration. Interestingly through breaking the symmetry of couplings an even lower 2t_ent ~6.3 {\mu}s can be achieved. This simulation not only explains the luminescence spectra in recently observed three-NV centers [Haruyama, Nat. Commun. 2019] but also shows a large improvement of the entanglement in artificially created structures through a cyclic redistribution of couplings. Realistically disordered coupling configurations of NV centers qubits with short time periods and high (0.89-0.99) fidelity of states clearly demonstrate possibility of accurate quantum registers operated at room temperature.