Spin configurations and quasiparticle fractional charge of fractional-quantum-Hall-effect ground states in theN=0Landau level

Spin configurations of fractions z<{ν}<2 are examined by angular and n-dependent activation studies. Energy gaps {Δ}({θ}) and intercepts σₓₓᶜ({θ}) that probe the quasiparticle charge e* quantify a dramatic difference between (4/3 and (5/3 states consistent with assignments (4/3{↑}{↓}, and (5/3{↑}{↑} ({↑}{↓},{↑}{↑}=zero, maximum polarization). A field-induced phase transition ₃⁴→₃⁴ (partial polarization) in which e* changes from e/3 to e/5 is mapped out. The (7/5 state formed from e/3 quasiparticles is destroyed at the (4/3 transition. High-order assignments ₅⁷({↑}{↑} or {↓}), ₅⁸ {↑}{↓}, ₇¹⁰ {↑}{↓}, and ₇¹¹↑ are consistent with experiment.