Generalized tricircular projections on minimal norm ideals in B(H)

A nonzero projection P on a complex Banach space X is said to be a generalized tricircular projection if there exist distinct modulus one complex numbers λ and μ, not equal to 1, and nonzero projections Q and R on X such that P⊕Q⊕R=I and P+λQ+μR is an isometry. We determine the structure of generalized tricircular projections on minimal norm ideals in B(H), different from the Hilbert-Schmidt class.