  Recent studies have shown that linear electron optics can be used to generate
entangled two-particle states from nonentangled ones if additional measurements
of charge or parity are performed. We have investigated such nondeterministic
entanglement production in electronic versions of the Mach-Zehnder
interferometer, where spin-dependent interference occurs due to the presence of
electric-field tunable Rashba spin splitting. Adjustment of the spin-precession
length turns out to switch the entangler on and off, as well as control the
detailed form of entangled output states.
