Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Article
  • Published:

Direct observation of geometric-phase interference in dynamics around a conical intersection

Abstract

Conical intersections are ubiquitous in chemistry and physics, often governing processes such as light harvesting, vision, photocatalysis and chemical reactivity. They act as funnels between electronic states of molecules, allowing rapid and efficient relaxation during chemical dynamics. In addition, when a reaction path encircles a conical intersection, the molecular wavefunction experiences a geometric phase, which can affect the outcome of the reaction through quantum-mechanical interference. Past experiments have measured indirect signatures of geometric phases in scattering patterns and spectroscopic observables, but there has been no direct observation of the underlying wavepacket interference. Here we experimentally observe geometric-phase interference in the dynamics of a wavepacket travelling around an engineered conical intersection in a programmable trapped-ion quantum simulator. To achieve this, we develop a technique to reconstruct the two-dimensional wavepacket densities of a trapped ion. Experiments agree with the theoretical model, demonstrating the ability of analogue quantum simulators—such as those realized using trapped ions—to accurately describe nuclear quantum effects.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Fig. 1: Directly detecting a geometric phase through wavepacket interference.
Fig. 2: Experimental protocol for geometric-phase dynamics simulation and wavepacket reconstruction.
Fig. 3: Wavepacket dynamics around an engineered conical intersection.

Similar content being viewed by others

Data availability

A repository containing data plotted in Fig. 3 and in Extended Data Fig. 1 is available at https://doi.org/10.5281/zenodo.7955887 (ref. 55).

References

  1. Yarkony, D. R. Diabolical conical intersections. Rev. Mod. Phys. 68, 985 (1996).

    Article  CAS  Google Scholar 

  2. Domcke, W., Yarkony, D. R. & Köppel, H. Conical Intersections: Electronic Structure, Dynamics and Spectroscopy (World Scientific, 2004).

  3. Larson, J., Sjöqvist, E. & Öhberg, P. Conical Intersections in Physics (Springer, 2020).

  4. Domcke, W. & Yarkony, D. R. Role of conical intersections in molecular spectroscopy and photoinduced chemical dynamics. Annu. Rev. Phys. Chem. 63, 325–352 (2012).

    Article  CAS  PubMed  Google Scholar 

  5. Berry, M. V. Quantal phase factors accompanying adiabatic changes. Proc. R. Soc. Lond. A 392, 45–57 (1984).

    Article  Google Scholar 

  6. Longuet-Higgins, H. C., Öpik, U., Pryce, M. H. L. & Sack, R. A. Studies of the Jahn–Teller effect II. The dynamical problem. Proc. R. Soc. Lond. A 244, 1–16 (1958).

    Article  CAS  Google Scholar 

  7. Mead, C. A. & Truhlar, D. G. On the determination of Born–Oppenheimer nuclear motion wave functions including complications due to conical intersections and identical nuclei. J. Chem. Phys. 70, 2284–2296 (1979).

    Article  CAS  Google Scholar 

  8. Schön, J. & Köppel, H. Geometric phase effects and wave packet dynamics on intersecting potential energy surfaces. J. Chem. Phys. 103, 9292–9303 (1995).

    Article  Google Scholar 

  9. Ryabinkin, I. G., Joubert-Doriol, L. & Izmaylov, A. F. Geometric phase effects in nonadiabatic dynamics near conical intersections. Acc. Chem. Res. 50, 1785–1793 (2017).

    Article  CAS  PubMed  Google Scholar 

  10. Mead, C. A. Superposition of reactive and nonreactive scattering amplitudes in the presence of a conical intersection. J. Chem. Phys. 72, 3839–3840 (1980).

    Article  CAS  Google Scholar 

  11. Lepetit, B. & Kuppermann, A. Numerical study of the geometric phase in the H + H2 reaction. Chem. Phys. Lett. 166, 581–588 (1990).

    Article  CAS  Google Scholar 

  12. Althorpe, S. C. General explanation of geometric phase effects in reactive systems: unwinding the nuclear wave function using simple topology. J. Chem. Phys. 124, 084105 (2006).

    Article  PubMed  Google Scholar 

  13. Althorpe, S. C., Stecher, T. & Bouakline, F. Effect of the geometric phase on nuclear dynamics at a conical intersection: extension of a recent topological approach from one to two coupled surfaces. J. Chem. Phys. 129, 214117 (2008).

    Article  PubMed  Google Scholar 

  14. Kendrick, B. Geometric phase effects in the vibrational spectrum of Na3(X). Phys. Rev. Lett. 79, 2431–2434 (1997).

    Article  CAS  Google Scholar 

  15. Applegate, B. E., Barckholtz, T. A. & Miller, T. A. Explorations of conical intersections and their ramifications for chemistry through the Jahn–Teller effect. Chem. Soc. Rev. 32, 38–49 (2003).

    Article  CAS  PubMed  Google Scholar 

  16. Englman, R. Spectroscopic detectability of the molecular Aharonov–Bohm effect. J. Chem. Phys. 144, 024103 (2016).

    Article  CAS  PubMed  Google Scholar 

  17. Yuan, D. et al. Observation of the geometric phase effect in the H + HD → H2 + D reaction. Science 362, 1289–1293 (2018).

    Article  CAS  PubMed  Google Scholar 

  18. Yuan, D. et al. Observation of the geometric phase effect in the H + HD → H2 + D reaction below the conical intersection. Nat. Commun. 11, 3640 (2020).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  19. Cina, J. A. & Romero Rochin, V. Optical impulsive excitation of molecular pseudorotation in Jahn–Teller systems. J. Chem. Phys. 93, 3844–3849 (1990).

    Article  CAS  Google Scholar 

  20. Cina, J. A. Phase-controlled optical pulses and the adiabatic electronic sign change. Phys. Rev. Lett. 66, 1146–1149 (1991).

    Article  CAS  PubMed  Google Scholar 

  21. Cina, J. A., Smith, T. J. Jr & Romero-Rochin, V. Advances in Chemical Physics (John Wiley & Sons, 1993).

  22. Castro Neto, A. H., Guinea, F., Peres, N. M. R., Novoselov, K. S. & Geim, A. K. The electronic properties of graphene. Rev. Mod. Phys. 81, 109 (2009).

    Article  CAS  Google Scholar 

  23. Ran, Y., Wang, F., Zhai, H., Vishwanath, A. & Lee, D.-H. Nodal spin density wave and band topology of the FeAs-based materials. Phys. Rev. B 79, 014505 (2009).

    Article  Google Scholar 

  24. Rashba, E. I. Symmetry of energy bands in wurtzite-type crystals. I. Symmetry of bands neglecting the spin–orbit interaction. Sov. Phys.-Solid State 1, 368 (1959).

    CAS  Google Scholar 

  25. Dresselhaus, G. Spin–orbit coupling effects in zinc blende structures. Phys. Rev. 100, 580 (1955).

    Article  CAS  Google Scholar 

  26. Cina, J. A. Wave-packet interferometry and molecular state reconstruction: spectroscopic adventures on the left-hand side of the Schrödinger equation. Annu. Rev. Phys. Chem. 59, 319–342 (2008).

    Article  CAS  PubMed  Google Scholar 

  27. Buluta, I. & Nori, F. Quantum simulators. Science 326, 108–111 (2009).

    Article  CAS  PubMed  Google Scholar 

  28. Blatt, R. & Roos, C. F. Quantum simulations with trapped ions. Nat. Phys. 8, 277–284 (2012).

    Article  CAS  Google Scholar 

  29. Aspuru-Guzik, A. & Walther, P. Photonic quantum simulators. Nat. Phys. 8, 285–291 (2012).

    Article  CAS  Google Scholar 

  30. McArdle, S., Endo, S., Aspuru-Guzik, A., Benjamin, S. C. & Yuan, X. Quantum computational chemistry. Rev. Mod. Phys. 92, 015003 (2020).

    Article  CAS  Google Scholar 

  31. Gorman, J. D. et al. Engineering vibrationally assisted energy transfer in a trapped-ion quantum simulator. Phys. Rev. X 8, 011038 (2018).

    CAS  Google Scholar 

  32. Duca, L. et al. An Aharonov–Bohm interferometer for determining Bloch band topology. Science 347, 288–292 (2015).

    Article  CAS  PubMed  Google Scholar 

  33. Brown, C. D. et al. Direct geometric probe of singularities in band structure. Science 377, 1319–1322 (2022).

    Article  CAS  PubMed  Google Scholar 

  34. Gambetta, F. M., Zhang, C., Hennrich, M., Lesanovsky, I. & Li, W. Exploring the many-body dynamics near a conical intersection with trapped Rydberg ions. Phys. Rev. Lett. 126, 233404 (2021).

    Article  CAS  PubMed  Google Scholar 

  35. Dereli, T., Gül, Y., Forn-Díaz, P. & Müstecaplğlu, O. E. Two-frequency Jahn–Teller systems in circuit QED. Phys. Rev. A 85, 053841 (2012).

    Article  Google Scholar 

  36. Larson, J. Jahn–Teller systems from a cavity QED perspective. Phys. Rev. A 78, 033833 (2008).

    Article  Google Scholar 

  37. Wang, C. S. et al. Observation of wave-packet branching through an engineered conical intersection. Phys. Rev. X 13, 011008 (2023).

    CAS  Google Scholar 

  38. MacDonell, R. J. et al. Analog quantum simulation of chemical dynamics. Chem. Sci. 12, 9794–9805 (2021).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  39. MacDonell, R. J. et al. Predicting molecular vibronic spectra using time-domain analog quantum simulation. Preprint at arXiv https://doi.org/10.48550/arXiv.2209.06558 (2022).

  40. Bersuker, I. B. Modern aspects of the Jahn–Teller effect: theory and applications to molecular problems. Chem. Rev. 101, 1067–1114 (2001).

    Article  CAS  PubMed  Google Scholar 

  41. Monroe, C., Meekhof, D. M., King, B. E. & Wineland, D. J. A ‘Schrödinger cat’ superposition state of an atom. Science 272, 1131–1136 (1996).

    Article  CAS  PubMed  Google Scholar 

  42. Mizrahi, J. et al. Quantum control of qubits and atomic motion using ultrafast laser pulses. Appl. Phys. B 114, 45–61 (2014).

    Article  CAS  Google Scholar 

  43. Leibfried, D. et al. Experimental determination of the motional quantum state of a trapped atom. Phys. Rev. Lett. 77, 4281–4285 (1996).

    Article  CAS  PubMed  Google Scholar 

  44. Gerritsma, R. et al. Quantum simulation of the Dirac equation. Nature 463, 68–71 (2010).

    Article  CAS  PubMed  Google Scholar 

  45. Johnson, K. G., Neyenhuis, B., Mizrahi, J., Wong-Campos, J. D. & Monroe, C. Sensing atomic motion from the zero point to room temperature with ultrafast atom interferometry. Phys. Rev. Lett. 115, 213001 (2015).

    Article  CAS  PubMed  Google Scholar 

  46. Flühmann, C. & Home, J. P. Direct characteristic-function tomography of quantum states of the trapped-ion motional oscillator. Phys. Rev. Lett. 125, 043602 (2020).

    Article  PubMed  Google Scholar 

  47. Jia, Z. et al. Determination of multimode motional quantum states in a trapped ion system. Phys. Rev. Lett. 129, 103602 (2022).

    Article  CAS  PubMed  Google Scholar 

  48. Hayes, D., Flammia, S. T. & Biercuk, M. J. Programmable quantum simulation by dynamic Hamiltonian engineering. New J. Phys. 16, 083027 (2014).

    Article  Google Scholar 

  49. Brownnutt, M., Kumph, M., Rabl, P. & Blatt, R. Ion-trap measurements of electric-field noise near surfaces. Rev. Mod. Phys. 87, 1419 (2015).

    Article  CAS  Google Scholar 

  50. Kienzler, D. et al. Observation of quantum interference between separated mechanical oscillator wave packets. Phys. Rev. Lett. 116, 140402 (2016).

    Article  CAS  PubMed  Google Scholar 

  51. Whitlow, J. et al. Simulating conical intersections with trapped ions. Preprint at arXiv https://doi.org/10.48550/arXiv.2211.07319 (2022).

  52. Monroe, C. et al. Resolved-sideband Raman cooling of a bound atom to the 3D zero-point energy. Phys. Rev. Lett. 75, 4011 (1995).

    Article  CAS  PubMed  Google Scholar 

  53. Wineland, D. J. et al. Experimental issues in coherent quantum-state manipulation of trapped atomic ions. J. Res. Natl Inst. Stand. Technol. 103, 259–328 (1998).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  54. Riesebos, L., Bondurant, B. & Brown, K. R. Universal graph-based scheduling for quantum systems. IEEE Micro 41, 57–65 (2021).

    Article  Google Scholar 

  55. Valahu, C. H. et al. Direct observation of geometric phase in dynamics around a conical intersection. Zenodo https://doi.org/10.5281/zenodo.7955887 (2023).

Download references

Acknowledgements

We thank J. Whitlow and K. Brown for valuable discussions. We were supported by the US Office of Naval Research Global (N62909-20-1-2047), by the US Army Research Office Laboratory for Physical Sciences (W911NF-21-1-0003), by the US Intelligence Advanced Research Projects Activity (W911NF-16-1-0070), by Lockheed Martin, by the Australian Government’s Defence Science and Technology Group, by the Sydney Quantum Academy (V.C.O.-A., A.D.R., M.J.M. and T.R.T.), by a USyd–UCSD Partnership Collaboration Award (J.B.P.-S., J.Y.-Z. and I.K.), by H. and A. Harley, and by computational resources from the Australian Government’s National Computational Infrastructure (Gadi) through the National Computational Merit Allocation Scheme.

Author information

Authors and Affiliations

Authors

Contributions

R.J.M., I.K., C.H. and T.R.T. conceived the original idea. V.C.O.-A., R.J.M., J.B.P.-S., J.Y.-Z. and I.K. developed the theoretical methods. C.H.V., T.N., A.D.R., M.J.M. and T.R.T. carried out the experiments. C.H.V., V.C.O.-A., T.R.T. and I.K. wrote the manuscript with feedback from all authors. All authors discussed the results and interpreted the data.

Corresponding authors

Correspondence to T. R. Tan or I. Kassal.

Ethics declarations

Competing interests

The authors declare no competing interests.

Peer review

Peer review information

Nature Chemistry thanks Jeffrey Cina and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

Additional information

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Extended data

Extended Data Fig. 1 Characteristic functions of the wavepacket measured for various evolution times.

a-d Joint two-dimensional characteristic function χ(iβ1, iβ2) = pχ(iβ1, iβ2) + pχ(iβ1, iβ2) measured at times t = {0, 0.9T, T, 2T} using the full pulse sequence of Fig. 2. The real (left) and imaginary (right) parts are measured with and without an Rx(π/2) pulse in the reconstruction. The top row shows theoretical predictions and the bottom experimental results. χ(iβ1, iβ2) were measured in the range β1, β2 [0, 4] with 11 × 11 equidistant samples (dashed quadrant). Values in the remaining three quadrants are obtained from the symmetry of χ(iβ1, iβ2). e One-dimensional characteristic functions χ(iβ2) and χ(iβ2) obtained by omitting displacements on B1 in the reconstruction. β2 was uniformly sampled in the range [0, 5] with 26 points. Each two- and one-dimensional characteristic function was averaged over 1000 and 2000 measurements, respectively. Error bars in e represent one standard deviation based on quantum projection noise.

Extended Data Fig. 2 Frequency drifts of radial motional modes.

a Time series of motional frequencies ω1,2 corresponding to B1,2, measured using the calibration routine detailed in the text and plotted as the frequency offset from ω1 measured at t = 0. b Allan deviation of ω1, and of the difference between the two frequencies (ω1 − ω2).

Rights and permissions

Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Valahu, C.H., Olaya-Agudelo, V.C., MacDonell, R.J. et al. Direct observation of geometric-phase interference in dynamics around a conical intersection. Nat. Chem. 15, 1503–1508 (2023). https://doi.org/10.1038/s41557-023-01300-3

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/s41557-023-01300-3

This article is cited by

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing