Quantum control in two-dimensional Fourier-transform spectroscopy

Abstract

We present a method that harnesses coherent control capability to two-dimensional Fourier-transform optical spectroscopy. For this, three ultrashort laser pulses are individually shaped to prepare and control the quantum interference involved in two-photon interexcited-state transitions of a V-type quantum system. In experiments performed with atomic rubidium, quantum control for the enhancement and reduction of the 5P 1/2 → 5P 3/2 transition was successfully tested in which the engineered transitions were distinguishably extracted in the presence of dominant one-photon transitions.

Quantum dynamics of a two-state system induced by a chirped zero-area pulse

“…This approach can be a powerful and alternative control means in selective excitation of, in particular, multi-state systems. In a V -type system [28] of 5S 1/2 , 5P 1/2 , and 5P 3/2 in rubidium, for example, a numerical simulation (not shown) with chirped zero-area pulses results in over 97% population of the system driven to either excited states, by simply changing the pulse intensity only. Also, this control method implicates that the laser spatial profile is also useful for position-dependent selective excitations, which can be applied to, for example, atom or ion qubits in spatial arrangements [29,30].…”

“…Localized CPR regions appear as spots around A , B , · · · , E ; and CPI regions as strips, e.g., along 1 -6 . The dotted lines indicate contours for the estimated rotation angles Θ1 and Θ2 defined by Eqs (28). and(30).…”

Quantum interference control of a four-level diamond-configuration quantum system

“…The spectral-phase-function solution of a femtosecond pulse, which maximizes the net two-photon transition in the three-level ladder-configuration system, is known as φ(ω) = 0, π/2, and 0 for ω ∈ (−∞,ω ig ), (ω ig ,ω f i ), and (ω f i , + ∞), respectively [8]. Likewise, for a three-level V-configuration system, the solution is known as φ(ω) = 0, 3π/2, and 0 for ω ∈ (−∞,ω ig ), (ω ig ,ω f i ), and (ω f i , + ∞), respectively [13,14].…”

Terahertz substance imaging by waveform shaping

“…As for the pulse-shaping, there has been much interest in optical frequency domain, in part because of its applications in telecommunication and signal processing [6], and in part because of its potential use as a new optical means toward selective control of electronic and vibrational response of materials [7][8][9][10]. Of particular relevance in the context of the present paper is the coherent control spectroscopy introduced by Ogilvie and co-workers, where the nonlinear nature of two-photon fluorescence provided by shaped optical fields has been exploited for selective substance microscopy of biological materials [11].…”