English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

In an external magnetic field B, the spins of the electron and hole willprecess in effective fields b_e + B and b_h + B, where b_e and b_h are randomhyperfine fields acting on the electron and hole, respectively. For sparse"soft" pairs the magnitudes of these effective fields coincide. The dynamics ofprecession for these pairs acquires a slow component, which leads to a slowingdown of recombination. We study the effect of soft pairs on organicmagnetoresistance, where slow recombination translates into blocking of thepassage of current. It appears that when b_e and b_h have identical gaussiandistributions the contribution of soft pairs to the current does not depend onB. Amazingly, small inequivalence in the rms values of b_e and b_h gives riseto a magnetic field response, and it becomes progressively stronger as theinequivalence increases. We find the expression for this response by performingthe averaging over b_e, b_h analytically. Another source of magnetic fieldresponse in the regime when current is dominated by soft pairs is inequivalenceof the g-factors of the pair partners. Our analytical calculation indicatesthat for this mechanism the response has an opposite sign.

Slow dynamics of spin pairs in random hyperfine field: Role of inequivalence of electrons and holes in organic magnetoresistance