Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

The Journal of Physical Chemistry B

Sensitivity of the Extended STIRAP Method of Selective Population Transfer to Coupling to Background States

Vandana Kurkal, Stuart A. Rice

Published Mar 29, 2001• 25 citations
Publisher

Abstract

The Kobrak-Rice extended STIRAP approach for selective population transfer has been tested for robustness vis a vis coupling to background states by examining preferential transfer to one or the other of nearly degenerate target states in the thiophosgene molecule. The calculations were carried out first within the original Kobrak-Rice five state scheme and then with inclusion of successively larger numbers of background states that have off-resonance radiative coupling with the original five states. Population transfers were calculated with and without use of the rotating wave approximation to determine if inclusion of the background states degraded the accuracy of that approximation. It is shown that the selective population transfer to a particular one of a pair of degenerate states is insensitive to the couplings with the background states and to the use of the rotating wave approximation.

DOI
10.1021/jp004194g

Related papers

Variations on the Theme of Stimulated Raman Adiabatic Passagr: Control of Chemical Reactions

Suhail P. Shah, Vandana Kurkal, Stuart A. Rice

We describe the exploitation of adiabatic transfer of population between selected states of a molecule as a means for the control of product selectivity in a branching unimolecular reaction. The particular procedures employed to achieve that adiabatic transfer of population depend on the character of the spectrum of states of the molecule; the ones we consider are either extensions of, or are illuminated by, the STIRAP method. The results of studies of efficient selective population of one of a pair of nearly degenerate states in the thiophosgene molecule, and of efficient promotion of the HCN → CNH isomerization reaction, are reported. In the former case the adiabatic population transfer is achieved by use of the Kobrak-Rice extended STIRAP method, while in the latter case it is achieved by use of consecutive STIRAP processes. In both cases the efficiency of selective population transfer is shown to be insensitive to radiative

ACS symposium series•Jun 21, 2002•0 citations

Selective Vibrational Population Transfer using Combined Stimulated Raman Adiabatic Passage and Counter-Diabatic Fields

Shumpei Masuda, Stuart A. Rice

We report studies of state-to-state vibrational energy transfer in an isolated polyatomic molecule driven by combined stimulated Raman adiabatic passage (STIRAP) and counter-diabatic fields (CDFs). The goal of these studies is development of a method for improving the efficiency of level-to-level population transfer under conditions that degrade the efficiency of conventional STIRAP-generated population transfer. The vehicles for our studies are selective population of one of a pair of near-degenerate states in nonrotating SCCl 2 and enhancing the yield of nonrotating HNC in the HCN → HNC isomerization reaction. The efficiency of the population transfer within a subset of states embedded in a manifold of states is examined for the cases in which the transition dipole moments between the initial and target states are much smaller than and comparable to the transition dipole moments between background states and for the case in which the subset states have large transition dipole moments with the background states. We show that, in a subset of states that is coupled to background states, a combination of STIRAP fields and CDFs that do not individually generate processes that are competitive with the desired population transfer can generate population transfer efficiency greater than can ordinary STIRAP with field strength and/or pulse duration similarly restricted and that the exact CDF for an isolated three-level system is a useful approximation to the exact CDF for three- and five-state systems embedded in background states. We report a study of the stability of the STIRAP and approximate CDF control protocol to variation of the CDF intensity, the relative phase between the STIRAP and CDFs, and the pulse duration.

The Journal of Physical Chemistry C•Oct 27, 2014•24 citations

Selective Vibrational Population Transfer using Combined STIRAP and Counter-Diabatic Fields

Shumpei Masuda, Stuart A. Rice

We report studies of state-to-state vibrational energy transfer in an isolated polyatomic molecule driven by combined stimulated Raman adiabatic passage (STIRAP) and counter-diabatic fields (CDF), using as vehicles selective population of one of a pair of near degenerate states in SCCl$_2$ and enhancing the yield of HNC in the HCN/HNC isomerization reaction. The efficiency of the population transfer within a subset of states embedded in a dense manifold of states is examined for the cases that the transition dipole moments between the initial and target states are much smaller than and comparable to the transition dipole moments between background states, and for the case that the subset states have large transition dipole moments with the background states. We show that, in a subset of states that is coupled to background states, a combination of STIRAP fields and CDFs that do not individually generate processes that are competitive with the desired population transfer can generate greater population transfer efficiency than can ordinary STIRAP with field strength and/or pulse duration similarly restricted. We also show that the exact CDF for an isolated three level system is a useful approximation to the exact CDF for three and five state systems embedded in background states, and we report a study of the stability of the STIRAP + approximate CDF control protocol to variation of the CDF.

arXiv:1409.0784•Sep 2, 2014•2 citations

Population Transfer to a Predissociating Target State Using Pulsed Coherent Excitation: Sensitivity to Coupling to Background States

Vandana Kurkal, Stuart A. Rice

We have examined the sensitivity to the presence of background states of population transfer to a predissociating molecular state generated by coherent two-pulse excitation. The system studied is intended to model optical control of the formation of a product in a photofragmentation reaction. The model spectrum of states is a generalization of the three-state spectrum considered in the conventional STIRAP method in three respects: the target state is a resonance in the continuum, the spectrum includes both unoccupied background states that have finite lifetimes and some unoccupied pairs of background states that are in resonance with the excitation pulses, and nonadiabatic population transfer is allowed. We examine the variation of the population transfer to the target state with respect to its lifetime, as well as the robustness of the population transfer with respect to variation of the area of overlap of the two excitation pulses and with respect to the presence of background states (some of which have finite lifetimes). Our results show that there is a broad range of conditions under which it is possible to transfer population efficiently from an initial state to a target predissociating state using coherent two-pulse excitation, although that population transfer is not always adiabatic.

The Journal of Physical Chemistry A•Aug 16, 2002•10 citations

Selective photochemistry via adiabatic passage: An extension of stimulated Raman adiabatic passage for degenerate final states

Mark N. Kobrak, Stuart A. Rice

In this paper we extend the existing theory of stimulated Raman adiabatic passage (StiRAP) in three-level systems to examine the nature of selective photoexcitation using counterintuitively ordered pulses. Our goal is to develop a version of StiRAP that permits control of product selectivity in a chemical reaction. We analyze the case of selective excitation to one state in a pair of degenerate target states in a four-level system, and find that one cannot control the ratio of the populations in the two states in a resonant two-photon process. However, the extension of the system to include a fifth state and a third laser field makes selective excitation to one of the degenerate states possible. It is found that, subject to reasonable restrictions, one may accomplish complete population transfer to a single target state of a degenerate pair of states in a five-level system.

Physical Review A•Apr 1, 1998•85 citations

Limitations of STIRAP-like population transfer in extended systems: The three-level system embedded in a web of background states

Werner Jakubetz

This paper presents a systematic numerical investigation of background state participation in STIRAP (stimulated Raman-adiabatic passage) population transfer among vibrational states, focusing on the consequences for the robustness of the method. The simulations, which are performed over extended grids in the parameter space of the Stokes- and pump pulses (frequencies, field strengths, and pulse lengths), involve hierarchies of (3 + N)-level systems of increasing complexity, ranging from the standard three-level STIRAP setup, (N = 0) in Λ-configuration, up to N = 446. A strongly coupled three-level core system is selected from the full Hamiltonian of the double-well HCN∕HNC system, and the couplings connecting this core system to the remaining states are (re-) parameterized in different ways, from very weak to very strong. The systems so obtained represent a three-level system embedded in various ways in webs of cross-linked vibrational background states and incorporate typical molecular properties. We first summarize essential properties of population transfer in the standard three-level system and quantify the robustness of the method and its dependence on the pulse parameters. Against these reference results, we present results obtained for four (3 + 446)-level systems and several subsystems. For pulse lengths of at most few picoseconds the intrinsic robustness of STIRAP with respect to variations in the field strength disappears as soon as the largest core-background couplings exceed about one tenth of the STIRAP couplings. In such cases robustness with respect to variations in the field strength is entirely lost, since at higher field strengths, except for irregularly spaced narrow frequency ranges, transfer probabilities are strongly reduced. STIRAP-like population transfer is maintained, with some restrictions, at low field strengths near the onset of adiabatic transfer. The suppression of STIRAP is traced back to different mechanisms based on a plentitude of single- and multiphoton transitions to background states, which at the high field strengths characteristic for STIRAP proceed readily even along weakly coupled pathways.

The Journal of Chemical Physics•Dec 13, 2012•16 citations
The Kobrak-Rice extended STIRAP approach for selective population transfer has been tested for robustness vis a vis coupling to background states by examining preferential transfer to one or the other of nearly degenerate target states in the thiophosgene molecule. The calculations were carried out first within the original Kobrak-Rice five state scheme and then with inclusion of successively larger numbers of background states that have off-resonance radiative coupling with the original five states. Population transfers were calculated with and without use of the rotating wave approximation to determine if inclusion of the background states degraded the accuracy of that approximation. It is shown that the selective population transfer to a particular one of a pair of degenerate states is insensitive to the couplings with the background states and to the use of the rotating wave approximation.
We describe the exploitation of adiabatic transfer of population between selected states of a molecule as a means for the control of product selectivity in a branching unimolecular reaction. The particular procedures employed to achieve that adiabatic transfer of population depend on the character of the spectrum of states of the molecule; the ones we consider are either extensions of, or are illuminated by, the STIRAP method. The results of studies of efficient selective population of one of a pair of nearly degenerate states in the thiophosgene molecule, and of efficient promotion of the HCN → CNH isomerization reaction, are reported. In the former case the adiabatic population transfer is achieved by use of the Kobrak-Rice extended STIRAP method, while in the latter case it is achieved by use of consecutive STIRAP processes. In both cases the efficiency of selective population transfer is shown to be insensitive to radiative
We report studies of state-to-state vibrational energy transfer in an isolated polyatomic molecule driven by combined stimulated Raman adiabatic passage (STIRAP) and counter-diabatic fields (CDFs). The goal of these studies is development of a method for improving the efficiency of level-to-level population transfer under conditions that degrade the efficiency of conventional STIRAP-generated population transfer. The vehicles for our studies are selective population of one of a pair of near-degenerate states in nonrotating SCCl 2 and enhancing the yield of nonrotating HNC in the HCN → HNC isomerization reaction. The efficiency of the population transfer within a subset of states embedded in a manifold of states is examined for the cases in which the transition dipole moments between the initial and target states are much smaller than and comparable to the transition dipole moments between background states and for the case in which the subset states have large transition dipole moments with the background states. We show that, in a subset of states that is coupled to background states, a combination of STIRAP fields and CDFs that do not individually generate processes that are competitive with the desired population transfer can generate population transfer efficiency greater than can ordinary STIRAP with field strength and/or pulse duration similarly restricted and that the exact CDF for an isolated three-level system is a useful approximation to the exact CDF for three- and five-state systems embedded in background states. We report a study of the stability of the STIRAP and approximate CDF control protocol to variation of the CDF intensity, the relative phase between the STIRAP and CDFs, and the pulse duration.
We report studies of state-to-state vibrational energy transfer in an isolated polyatomic molecule driven by combined stimulated Raman adiabatic passage (STIRAP) and counter-diabatic fields (CDF), using as vehicles selective population of one of a pair of near degenerate states in SCCl2_22​ and enhancing the yield of HNC in the HCN/HNC isomerization reaction. The efficiency of the population transfer within a subset of states embedded in a dense manifold of states is examined for the cases that the transition dipole moments between the initial and target states are much smaller than and comparable to the transition dipole moments between background states, and for the case that the subset states have large transition dipole moments with the background states. We show that, in a subset of states that is coupled to background states, a combination of STIRAP fields and CDFs that do not individually generate processes that are competitive with the desired population transfer can generate greater population transfer efficiency than can ordinary STIRAP with field strength and/or pulse duration similarly restricted. We also show that the exact CDF for an isolated three level system is a useful approximation to the exact CDF for three and five state systems embedded in background states, and we report a study of the stability of the STIRAP + approximate CDF control protocol to variation of the CDF.
We have examined the sensitivity to the presence of background states of population transfer to a predissociating molecular state generated by coherent two-pulse excitation. The system studied is intended to model optical control of the formation of a product in a photofragmentation reaction. The model spectrum of states is a generalization of the three-state spectrum considered in the conventional STIRAP method in three respects: the target state is a resonance in the continuum, the spectrum includes both unoccupied background states that have finite lifetimes and some unoccupied pairs of background states that are in resonance with the excitation pulses, and nonadiabatic population transfer is allowed. We examine the variation of the population transfer to the target state with respect to its lifetime, as well as the robustness of the population transfer with respect to variation of the area of overlap of the two excitation pulses and with respect to the presence of background states (some of which have finite lifetimes). Our results show that there is a broad range of conditions under which it is possible to transfer population efficiently from an initial state to a target predissociating state using coherent two-pulse excitation, although that population transfer is not always adiabatic.
In this paper we extend the existing theory of stimulated Raman adiabatic passage (StiRAP) in three-level systems to examine the nature of selective photoexcitation using counterintuitively ordered pulses. Our goal is to develop a version of StiRAP that permits control of product selectivity in a chemical reaction. We analyze the case of selective excitation to one state in a pair of degenerate target states in a four-level system, and find that one cannot control the ratio of the populations in the two states in a resonant two-photon process. However, the extension of the system to include a fifth state and a third laser field makes selective excitation to one of the degenerate states possible. It is found that, subject to reasonable restrictions, one may accomplish complete population transfer to a single target state of a degenerate pair of states in a five-level system.
This paper presents a systematic numerical investigation of background state participation in STIRAP (stimulated Raman-adiabatic passage) population transfer among vibrational states, focusing on the consequences for the robustness of the method. The simulations, which are performed over extended grids in the parameter space of the Stokes- and pump pulses (frequencies, field strengths, and pulse lengths), involve hierarchies of (3 + N)-level systems of increasing complexity, ranging from the standard three-level STIRAP setup, (N = 0) in Λ-configuration, up to N = 446. A strongly coupled three-level core system is selected from the full Hamiltonian of the double-well HCN∕HNC system, and the couplings connecting this core system to the remaining states are (re-) parameterized in different ways, from very weak to very strong. The systems so obtained represent a three-level system embedded in various ways in webs of cross-linked vibrational background states and incorporate typical molecular properties. We first summarize essential properties of population transfer in the standard three-level system and quantify the robustness of the method and its dependence on the pulse parameters. Against these reference results, we present results obtained for four (3 + 446)-level systems and several subsystems. For pulse lengths of at most few picoseconds the intrinsic robustness of STIRAP with respect to variations in the field strength disappears as soon as the largest core-background couplings exceed about one tenth of the STIRAP couplings. In such cases robustness with respect to variations in the field strength is entirely lost, since at higher field strengths, except for irregularly spaced narrow frequency ranges, transfer probabilities are strongly reduced. STIRAP-like population transfer is maintained, with some restrictions, at low field strengths near the onset of adiabatic transfer. The suppression of STIRAP is traced back to different mechanisms based on a plentitude of single- and multiphoton transitions to background states, which at the high field strengths characteristic for STIRAP proceed readily even along weakly coupled pathways.