Effect of dephasing on stimulated Raman adiabatic passage

Abstract

This work explores the effect of phase relaxation on the population transfer efficiency in stimulated Raman adiabatic passage (STIRAP). The study is based on the Liouville equation, which is solved analytically in the adiabatic limit. The transfer efficiency of STIRAP is found to decrease exponentially with the dephasing rate; this effect is stronger for shorter pulse delays and weaker for larger delays, since the transition time is found to be inversely proportional to the pulse delay. Moreover, it is found that the transfer efficiency of STIRAP in the presence of dephasing does not depend on the peak Rabi frequencies at all, as long as they are sufficiently large to enforce adiabatic evolution; hence increasing the field intensity cannot reduce the dephasing losses. It is shown also that for any dephasing rate, the final populations of the initial state and the intermediate state are equal. For strong dephasing all three populations tend to 1 3 .

Efficient qubit detection using alkaline-earth-metal ions and a double stimulated Raman adiabatic process

“…The results are presented in Sec. 's IV and V. Here we use as an example the 40 Ca + ion, but, apart from different decay rates and wavelengths, our treatment is also valid for Sr + , Ba + and Hg + ions with no nuclear spin. In Sec.…”

“…In the simulations we use the specific wavelengths (λ A = 397 nm, λ B = 866 nm, λ C = 850 nm, λ D = 854 nm) and spontaneous decay rates (Γ 21 /2π = 21 MHz, Γ 23 /2π = 1.7 MHz, Γ 41 /2π = 22 MHz, Γ 43 /2π = 0.18 MHz, Γ 45 /2π = 1.6 MHz) for the 40 Ca + ion, but this apart the calculations are also valid for isotopes of Sr + , Ba + and Hg + with no nuclear spin (See relevant parameters for the most abundant isotopes in appendix). We use Gaussian pulses as defined in Eq.…”

“…This dephasing effect has been studied thoroughly in [40], where the STIRAP transfer efficiency has been shown to depend only on the dephasing rate between |3 and |5 , γ 35 .…”

“…The qubit states most successfully implemented with trapped ions are two hyperfine components of the 9 Be + ground state [12] and a combination of the metastable 3D 5/2 state and the 4S 1/2 ground state in 40 Ca + [13]. In both cases linear Paul traps are used to confine the ions.…”

Shot-noise-limited spin measurements in a pulsed molecular beam

“…4(a). Here unwanted adiabatic transfer between the | x/y states can occur due to coupling through the other parity component of the C-state doublet; the probability of such a transfer is P a ∼ exp (− 2 C τ r γ C /2 2 rms ) [25], where γ C = 1/τ C ≈ 2π × 300 kHz is the C state radiative linewidth [23], τ r ∼ 100 ns is the AOM switching time, and again C ≈ 2π × 51 MHz is the C state J = 1 -doublet splitting. This probability is negligible under our conditions.…”