TY - JOUR

T1 - Multiplet-to-net CIDEP conversion by MW-pulses with adiabatically ramped amplitude

AU - Ivanov, Konstantin L.

AU - Lukzen, Nikita N.

PY - 2019/1/1

Y1 - 2019/1/1

N2 - A method is proposed to manipulate electron spin order of spin-correlated radical pairs. As radical pairs are often born in a well-defined spin state, e.g. in the singlet state, they acquire Chemically Induced Dynamic Electron Polarisation (CIDEP). In the case of singlet-state preparation CIDEP is of the multiplet (or anti-phase) type resulting in reduction of EPR (electron paramagnetic resonance) signals due to overlap of absorptive and emissive lines in the spectrum. Here we propose to convert the singlet spin order into net magnetisation of the radical pair by applying a microwave field, with its amplitude slowly (adiabatically) reduced to zero. We demonstrate that by properly choosing the microwave frequency one can completely convert the singlet order into net polarisation of the radical pair with significant enhancement of the signal as compared to multiplet CIDEP. Calculations show that the technique is operative for both weakly coupled and strongly coupled spin pairs. Potential applications of the method are discussed.

AB - A method is proposed to manipulate electron spin order of spin-correlated radical pairs. As radical pairs are often born in a well-defined spin state, e.g. in the singlet state, they acquire Chemically Induced Dynamic Electron Polarisation (CIDEP). In the case of singlet-state preparation CIDEP is of the multiplet (or anti-phase) type resulting in reduction of EPR (electron paramagnetic resonance) signals due to overlap of absorptive and emissive lines in the spectrum. Here we propose to convert the singlet spin order into net magnetisation of the radical pair by applying a microwave field, with its amplitude slowly (adiabatically) reduced to zero. We demonstrate that by properly choosing the microwave frequency one can completely convert the singlet order into net polarisation of the radical pair with significant enhancement of the signal as compared to multiplet CIDEP. Calculations show that the technique is operative for both weakly coupled and strongly coupled spin pairs. Potential applications of the method are discussed.

KW - CIDEP

KW - multiplet polarisation

KW - Spin hyperpolarisation

KW - spin order conversion

KW - RADICAL PAIRS

KW - SPIN STATES

KW - ORDER

KW - MODEL

KW - POLARIZATION

KW - PHOTOSYNTHESIS

KW - EPR SPECTROSCOPY

UR - http://www.scopus.com/inward/record.url?scp=85060619435&partnerID=8YFLogxK

U2 - 10.1080/00268976.2018.1562121

DO - 10.1080/00268976.2018.1562121

M3 - Article

AN - SCOPUS:85060619435

VL - 117

SP - 2719

EP - 2731

JO - Molecular Physics

JF - Molecular Physics

SN - 0026-8976

IS - 19

ER -