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Waters MDJ, Wörner HJ. The ultrafast vibronic dynamics of ammonia's D̃ state. Phys Chem Chem Phys 2022; 24:23340-23349. [PMID: 36129030 DOI: 10.1039/d2cp03117e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Using vacuum-ultraviolet time-resolved velocity map imaging of photoelectrons, we study ultrafast coupled electronic and nuclear dynamics in low-lying Rydberg states of ammonia. Vibrationally-resolved internal vibrational relaxation (IVR) is observed in a progression of the e' bending modes. This vibrational progression is only observed in the D̃ state, and is lost upon ultrafast internal conversion to the C̃ and B̃ electronic states. Due to the ultrashort time scale of the internal conversion (ca. 64 fs), and the vibronic resolution, the non-adiabatic coupling vectors are identified and verified with ab initio calculations. The time-scale of this IVR process is highly surprising and significant because IVR is usually treated as an incoherent process that proceeds statistically, according to a "Fermi's Golden Rule"-like model, where the process scales with the available degrees of freedom. Here, we show that it can be highly non-statistical, restricted to only a very small subset of vibrational motions.
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Affiliation(s)
- Max D J Waters
- Laboratory for Physical Chemistry, ETH Zürich, Vladimir-Prelog-Weg 2, 8093, Zürich, Switzerland.
| | - Hans Jakob Wörner
- Laboratory for Physical Chemistry, ETH Zürich, Vladimir-Prelog-Weg 2, 8093, Zürich, Switzerland.
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2
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Fábri C, Marquardt R, Császár AG, Quack M. Controlling tunneling in ammonia isotopomers. J Chem Phys 2019; 150:014102. [DOI: 10.1063/1.5063470] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Csaba Fábri
- Laboratory of Molecular Structure and Dynamics, Institute of Chemistry, Eötvös Loránd University, Pázmány Péter sétány 1/A, H-1117 Budapest, Hungary
- MTA-ELTE Complex Chemical Systems Research Group, P.O. Box 32, H-1518 Budapest 112, Hungary
- Physical Chemistry, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Roberto Marquardt
- Physical Chemistry, ETH Zürich, CH-8093 Zürich, Switzerland
- Laboratoire de Chimie Quantique, Institut de Chimie UMR 7177 CNRS/Université de Strasbourg, 4, Rue Blaise Pascal CS 90032, 67081 Strasbourg Cedex, France
| | - Attila G. Császár
- Laboratory of Molecular Structure and Dynamics, Institute of Chemistry, Eötvös Loránd University, Pázmány Péter sétány 1/A, H-1117 Budapest, Hungary
- MTA-ELTE Complex Chemical Systems Research Group, P.O. Box 32, H-1518 Budapest 112, Hungary
| | - Martin Quack
- Physical Chemistry, ETH Zürich, CH-8093 Zürich, Switzerland
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Brown A, Pradhan E. Fitting potential energy surfaces to sum-of-products form with neural networks using exponential neurons. JOURNAL OF THEORETICAL & COMPUTATIONAL CHEMISTRY 2017. [DOI: 10.1142/s0219633617300014] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
In this paper, the use of the neural network (NN) method with exponential neurons for directly fitting ab initio data to generate potential energy surfaces (PESs) in sum-of-product form will be discussed. The utility of the approach will be highlighted using fits of CS2, HFCO, and HONO ground state PESs based upon high-level ab initio data. Using a generic interface between the neural network PES fitting, which is performed in MATLAB, and the Heidelberg multi-configuration time-dependent Hartree (MCTDH) software package, the PESs have been tested via comparison of vibrational energies to experimental measurements. The review demonstrates the potential of the PES fitting method, combined with MCTDH, to tackle high-dimensional quantum dynamics problems.
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Affiliation(s)
- Alex Brown
- Department of Chemistry, University of Alberta, Edmonton, AB, T6G 2G2, Canada
| | - E. Pradhan
- Department of Chemistry, University of Alberta, Edmonton, AB, T6G 2G2, Canada
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Shyshlov D, Berrios E, Gruebele M, Babikov D. On readout of vibrational qubits using quantum beats. J Chem Phys 2014; 141:224306. [PMID: 25494748 DOI: 10.1063/1.4903055] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Dmytro Shyshlov
- Chemistry Department, Marquette University, Milwaukee, Wisconsin 53201, USA
| | - Eduardo Berrios
- Department of Chemistry, Department of Physics and Center for Biophysics and Computational Biology, University of Illinois, Urbana, Illinois 61801, USA
| | - Martin Gruebele
- Department of Chemistry, Department of Physics and Center for Biophysics and Computational Biology, University of Illinois, Urbana, Illinois 61801, USA
| | - Dmitri Babikov
- Chemistry Department, Marquette University, Milwaukee, Wisconsin 53201, USA
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Sala M, Gatti F, Guérin S. Coherent destruction of tunneling in a six-dimensional model of NHD2: A computational study using the multi-configuration time-dependent Hartree method. J Chem Phys 2014; 141:164326. [DOI: 10.1063/1.4900518] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Matthieu Sala
- Laboratoire Interdisciplinaire Carnot de Bourgogne UMR 6303 CNRS, Université de Bourgogne, BP 47870, F-21078 Dijon, France
| | - Fabien Gatti
- CTMM, Institut Charles Gerhardt (UMR 5253), CC1501, Université Montpellier II, F-34095 Montpellier, Cedex 05, France
| | - Stéphane Guérin
- Laboratoire Interdisciplinaire Carnot de Bourgogne UMR 6303 CNRS, Université de Bourgogne, BP 47870, F-21078 Dijon, France
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Pradhan E, Carreón-Macedo JL, Cuervo JE, Schröder M, Brown A. Ab Initio Potential Energy and Dipole Moment Surfaces for CS2: Determination of Molecular Vibrational Energies. J Phys Chem A 2012. [DOI: 10.1021/jp309651r] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Ekadashi Pradhan
- Department of Chemistry, University of Alberta, Edmonton, Alberta
T6G 2G2 Canada
| | | | - Javier E. Cuervo
- Department of Chemistry, University of Alberta, Edmonton, Alberta
T6G 2G2 Canada
| | - Markus Schröder
- Department of Chemistry, University of Alberta, Edmonton, Alberta
T6G 2G2 Canada
| | - Alex Brown
- Department of Chemistry, University of Alberta, Edmonton, Alberta
T6G 2G2 Canada
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Shyshlov D, Babikov D. Complexity and simplicity of optimal control theory pulses shaped for controlling vibrational qubits. J Chem Phys 2012. [PMID: 23181317 DOI: 10.1063/1.4765344] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
In the context of molecular quantum computation the optimal control theory (OCT) is used to obtain shaped laser pulses for high-fidelity control of vibrational qubits. Optimization is done in time domain and the OCT algorithm varies values of electric field in each time step independently, tuning hundreds of thousands of parameters to find one optimal solution. Such flexibility is not available in experiments, where pulse shaping is done in frequency domain and the number of "tuning knobs" is much smaller. The question of possible experimental interpretations of theoretically found OCT solutions arises. In this work we analyze very accurate optimal pulse that we obtained for implementing quantum gate CNOT for the two-qubit system encoded into the exited vibrational states of thiophosgene molecule. Next, we try to alter this pulse by reducing the number of available frequency channels and intentionally introducing systematic and random errors (in frequency domain, by modifying the values of amplitudes and phases of different frequency components). We conclude that a very limited number of frequency components (only 32 in the model of thiophosgene) are really necessary for accurate control of the vibrational two-qubit system, and such pulses can be readily constructed using OCT. If the amplitude and phase errors of different frequency components do not exceed ±3% of the optimal values, one can still achieve accurate transformations of the vibrational two-qubit system, with gate fidelity of CNOT exceeding 0.99.
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Affiliation(s)
- Dmytro Shyshlov
- Department of Chemistry, Marquette University, PO Box 1881, Milwaukee, Wisconsin 53201, USA
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Sharma S, Singh H. Laser pulse shaping for optimal control of multiphoton dissociation in a diatomic molecule using genetic algorithm optimization. Chem Phys 2011. [DOI: 10.1016/j.chemphys.2011.10.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Studying molecular quantum dynamics with the multiconfiguration time-dependent Hartree method. WILEY INTERDISCIPLINARY REVIEWS-COMPUTATIONAL MOLECULAR SCIENCE 2011. [DOI: 10.1002/wcms.87] [Citation(s) in RCA: 147] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Zaari RR, Brown A. Effect of diatomic molecular properties on binary laser pulse optimizations of quantum gate operations. J Chem Phys 2011; 135:044317. [DOI: 10.1063/1.3617248] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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11
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The operations of quantum logic gates with pure and mixed initial states. J Chem Phys 2011; 134:134103. [DOI: 10.1063/1.3571597] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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12
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Mishima K, Yamashita K. Free-time and fixed end-point multi-target optimal control theory: Application to quantum computing. Chem Phys 2011. [DOI: 10.1016/j.chemphys.2010.10.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Pellegrini P, Vranckx S, Desouter-Lecomte M. Implementing quantum algorithms in hyperfine levels of ultracold polar molecules by optimal control. Phys Chem Chem Phys 2011; 13:18864-71. [DOI: 10.1039/c1cp21184f] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Bomble L, Lauvergnat D, Remacle F, Desouter-Lecomte M. Controlled full adder-subtractor by vibrational computing. Phys Chem Chem Phys 2010; 12:15628-35. [PMID: 20661490 DOI: 10.1039/c003687k] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The implementation of a quantum-controlled full adder-subtractor of two binary digits and of a "carry in" or a "borrow in" is simulated by encoding four qubits in the vibrational eigenstates of a tetra-atomic molecule (trans-HONO). The laser field of the gate is computed using optimal control theory by treating dynamics in full dimensionality. A controlled qubit enforces the addition or the subtraction. The global unitary transformation that connects the inputs to the outputs is driven by a single laser pulse. This decreases the duration of the operation and allows for a better use of the optical resources and for an improvement of the fidelity (>97%). Initialization and reading out are discussed. The timescale of the sequence initialization, gate and read out is<100 ps.
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Affiliation(s)
- Laëtitia Bomble
- Laboratoire de Chimie Physique, Université de Paris-Sud, UMR8000, Orsay, F-91405, France
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Marquardt R, Sanrey M, Gatti F, Le Quéré F. Full-dimensional quantum dynamics of vibrationally highly excited NHD2. J Chem Phys 2010; 133:174302. [DOI: 10.1063/1.3496374] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Worth GA, Sanz CS. Guiding the time-evolution of a molecule: optical control by computer. Phys Chem Chem Phys 2010; 12:15570-9. [PMID: 21052596 DOI: 10.1039/c0cp01740j] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The theory and computation of optical control has been developed over the last 25 years and is now a mature field of research. Initial work provided pictures of how control using light fields in simple systems may be achieved, for example using multiple excitation pathways or pulse sequences. The development of optimal control theory then provided a general method for guiding a system to its target using a shaped laser pulse. Combined with quantum dynamics simulations this has become a widely used tool, and has been applied to a range of systems to show what can be controlled. The present challenge is to gain more insight into the mechanism of control. In addition, methods need to be extended to reach the size of system of interest to technology. In this perspective article we shall give a brief overview of present capabilities and some of the recent developments in quantum dynamics and control simulations.
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