Optical Spin Polarization of a Narrow‐Linewidth Electron‐Spin Qubit in a Chromophore/Stable‐Radical System.

Qiu, Yunfan; Equbal, Asif; Lin, Chenjian; Huang, Yuheng; Brown, Paige J.; Young, Ryan M.; Krzyaniak, Matthew D.; Wasielewski, Michael R.

Photoexcited organic chromophores appended to stable radicals can serve as qubit and/or qudit candidates for quantum information applications. 1,6,7,12‐Tetra‐(4‐tert‐butylphenoxy)‐perylene‐3,4 : 9,10‐bis(dicarboximide) (tpPDI) linked to a partially deuterated α,γ‐bisdiphenylene‐β‐phenylallyl radical (BDPA‐d16) was synthesized and characterized by time‐resolved optical and electron paramagnetic resonance (EPR) spectroscopies. Photoexcitation of tpPDI‐BDPA‐d16 results in ultrafast radical‐enhanced intersystem crossing to produce a quartet state (Q) followed by formation of a spin‐polarized doublet ground state (D0). Pulse‐EPR experiments confirmed the spin multiplicity of Q and yielded coherence times of Tm=2.1±0.1 μs and 2.8±0.2 μs for Q and D0, respectively. BDPA‐d16 eliminates the dominant 1H hyperfine couplings, resulting in a single narrow line for both the Q and D0 states, which enhances the spectral resolution needed for good qubit addressability.

ELECTRON paramagnetic resonance spectroscopy; OPTICAL polarization; SPIN polarization; ELECTRON spin; ELECTRON paramagnetic resonance; HYPERFINE coupling; CHROMOPHORES

Angewandte Chemie, 2023, Vol 135, Issue 6, p1

0044-8249

Academic Journal

10.1002/ange.202214668