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

Science

Quantum mechanical double slit for molecular scattering

Haowen Zhou, William E. Perreault, Nandini Mukherjee, Richard N. Zare

Published Nov 18, 2021• 64 citations
Publisher

Abstract

Double slits with molecular states Despite decades of research, the role of quantum mechanical effects in molecular scattering has not yet been fully investigated and can still demonstrate fascinating results, even for simple triatomic systems. Zhou et al . show that the entangled bond axis orientations in the biaxial state of a deuterium molecule can act as the two slits of a double-slit interferometer for rotationally inelastic collision with a helium atom, giving rise to quantum interference between two indistinguishable pathways (see the Perspective by Wang and Yang). The present work presents an elegant example of quantum interference in molecular scattering that is conceptually similar to the famous Young’s optical double-slit experiment. The proposed molecular interferometer could be used to coherently control the phases in various molecular processes in future experiments. —YS

DOI
10.1126/science.abl4143

Related papers

A Bi-Axial Quantum State That Controls Molecular Collisions Like a Double-Slit Interferometer

William E. Perreault, Haowen Zhou, Nandini Mukherjee +1 more

To control molecular scattering, we consider hydrogen molecules prepared in a coherent superposition of m states within a single rovibrational (v, j) energy eigenstate using Stark-induced adiabatic Raman passage (SARP). Specifically, SARP can prepare a bi-axial state of the HD molecule in which the HD bond axis exists simultaneously in two possible alignments at right angles to one another with a well-defined relative phase. We show that scattering from this biaxial state will interfere, resulting in a φ -dependent scattering intensity distribution, where φ is the azimuthal angle about the collision velocity direction. Using the scattering matrix extracted from our experiments on the rotationally inelastic collisions of quantum state prepared HD at low temperatures, we calculate the differential scattering cross-section dσ/dΩ, which shows an interference pattern as function of θ and φ in the image plane perpendicular to the collision velocity. The calculated scattering image shows that scattering from the bi-axial state directs molecules along well-defined angles, corresponding to interference maxima. Thus, the bi-axial state behaves like a double slit for molecular scattering. Moreover, by rotating the polarizations of the SARP preparation lasers, we can control the interference thereby altering the scattering angular distribution. This molecular interferometer, which experimentally measures the relative phases of the scattering matrix elements, allows a direct test of theoretical calculations on important, fundamental collision processes.

Frontiers in Physics•May 28, 2021•6 citations

A Molecular Double Slit Paradigm

Spiros S. Skourtis, David N. Beratan, Theodore E. Simos +1 more

This contribution describes a simple model of a molecular interferometer. We consider an electron transfer molecule consisting of electron‐donating and electron‐acceptor parts that are connected by a bridge. The bridge provides two parallel tunneling pathways for electron transfer from donor to acceptor. In each pathway the electron can interact with a pathway‐specific bridge vibration. We study electron transfer from donor to acceptor mediated by inelastic tunneling, where the tunneling electron exchanges energy with the local bridge vibrations. When the tunneling electron excites or is excited by a bridge vibration specific to one of the tunneling pathways, the tunneling pathway is “labeled” and the interference between tunneling pathways is lost. We discuss types of molecules and optical‐spectroscopy experiments which could allow the observation of this effect.

AIP conference proceedings•Jan 1, 2007•10 citations

Quantum interference of molecules -- probing the wave nature of matter

Anu Venugopalan

The double slit interference experiment has been famously described by Richard Feynman as containing the "only mystery of quantum mechanics". The history of quantum mechanics is intimately linked with the discovery of the dual nature of matter and radiation. While the double slit experiment for light is easily undertsood in terms of its wave nature, the very same experiment for particles like the electron is somewhat more difficult to comprehend. By the 1920s it was firmly established that electrons have a wave nature. However, for a very long time, most discussions pertaining to interference experiments for particles were merely gedanken experiments. It took almost six decades after the establishment of its wave nature to carry out a 'double slit interference' experiment for electrons. This set the stage for interference experiments with larger particles. In the last decade there has been spectacular progress in matter-wave interefernce experiments. Today, molecules with over a hundred atoms can be made to interfere. In the following we discuss some of these exciting developments which probe new regimes of Nature, bringing us closer to the heart of quantum mechanics and its hidden mysteries.

arXiv:1211.3493•Nov 15, 2012•0 citations

Young’s double-slit experiment with atoms: A simple atom interferometer

O. Carnal, J. Mlynek

An atomic interferometer based on a Young's-type double-slit arrangement has been demonstrated. A supersonic beam of metastable helium atoms passes through a 2-\ensuremath{\mu}m-wide slit in a thin gold foil. This transversely coherent beam impinges on a second microfabricated transmission structure, consisting of two 1-\ensuremath{\mu}m-wide slits at a lateral distance of 8 \ensuremath{\mu}m. This double slit defines two possible paths on which the atoms can reach the detector slit. The good visibility of the observed fringes should make it possible to measure differential phase shifts in the interferometer of 1/3 rad in less than 10 min.

Physical Review Letters•May 27, 1991•627 citations

Interference of cavity light by a single atom acting as a double slit

Yijia Zhou, Xinwei Li, Weibin Li +1 more

Young's double-slit interference experiment is central to quantum mechanics. While it has been demonstrated that an array of atoms can produce interference in light, it is a fundamental question to ask whether a single atom can act as a double slit when prepared in a superposition of two separate positions. Cohen-Tannoudji et al. [Proceedings of the Tenth International Conference on Laser Spectroscopy, edited by M. Ducloy, E. Giacobino, and G. Camy (World Scientific, Singapore, 1992), pp. 3--14] showed that the cross section of the light scattered by a single atom is independent of the spatial separation. In this work, however, we show that when a single atom tunneling in a double well is coupled to an optical ring cavity, the interference phenomena arise if the tunneling rate is comparable to the cavity linewidth. Being driven by an external laser in the dispersive regime, the field emitted by the atom into the cavity exhibits an interference pattern when varying the double-well spacing. Super-Poissonian bunched light can also be generated near the destructive interference. Furthermore, we show that the atomic flux of the coherent tunneling motion generates directional cavity emission, which oscillates for many cycles before the decoherence of the atomic motion and the decay of the cavity photons. Our work opens ways to manipulate photons with controllable external states of atoms for quantum information applications and use cavity light as nondestructive measurements for many-body states of atomic systems.

arXiv:2306.07037•Physical Review A•Dec 20, 2023•0 citations

Angular Momentum Sensitive Two-Center Interference

Markus Ilchen, Leif Glaser, Frank R. Scholz +16 more

In quantum mechanics the Young-type double-slit experiment can be performed with electrons either traveling through a double slit or being coherently emitted from two inversion symmetric molecular sites. In the latter one the valence photoionization cross sections of homonuclear diatomic molecules were predicted to oscillate over kinetic energy almost 50 years ago. Beyond the direct proof of the oscillatory behavior of these photoionization cross sections σ, we show that the angular distribution of the emitted electrons reveals hitherto unexplored information on the relative phase shift between the corresponding partial waves through two-center interference patterns.

Physical Review Letters•Jan 15, 2014•31 citations
Double slits with molecular states Despite decades of research, the role of quantum mechanical effects in molecular scattering has not yet been fully investigated and can still demonstrate fascinating results, even for simple triatomic systems. Zhou et al . show that the entangled bond axis orientations in the biaxial state of a deuterium molecule can act as the two slits of a double-slit interferometer for rotationally inelastic collision with a helium atom, giving rise to quantum interference between two indistinguishable pathways (see the Perspective by Wang and Yang). The present work presents an elegant example of quantum interference in molecular scattering that is conceptually similar to the famous Young’s optical double-slit experiment. The proposed molecular interferometer could be used to coherently control the phases in various molecular processes in future experiments. —YS
To control molecular scattering, we consider hydrogen molecules prepared in a coherent superposition of m states within a single rovibrational (v, j) energy eigenstate using Stark-induced adiabatic Raman passage (SARP). Specifically, SARP can prepare a bi-axial state of the HD molecule in which the HD bond axis exists simultaneously in two possible alignments at right angles to one another with a well-defined relative phase. We show that scattering from this biaxial state will interfere, resulting in a φ -dependent scattering intensity distribution, where φ is the azimuthal angle about the collision velocity direction. Using the scattering matrix extracted from our experiments on the rotationally inelastic collisions of quantum state prepared HD at low temperatures, we calculate the differential scattering cross-section dσ/dΩ, which shows an interference pattern as function of θ and φ in the image plane perpendicular to the collision velocity. The calculated scattering image shows that scattering from the bi-axial state directs molecules along well-defined angles, corresponding to interference maxima. Thus, the bi-axial state behaves like a double slit for molecular scattering. Moreover, by rotating the polarizations of the SARP preparation lasers, we can control the interference thereby altering the scattering angular distribution. This molecular interferometer, which experimentally measures the relative phases of the scattering matrix elements, allows a direct test of theoretical calculations on important, fundamental collision processes.
This contribution describes a simple model of a molecular interferometer. We consider an electron transfer molecule consisting of electron‐donating and electron‐acceptor parts that are connected by a bridge. The bridge provides two parallel tunneling pathways for electron transfer from donor to acceptor. In each pathway the electron can interact with a pathway‐specific bridge vibration. We study electron transfer from donor to acceptor mediated by inelastic tunneling, where the tunneling electron exchanges energy with the local bridge vibrations. When the tunneling electron excites or is excited by a bridge vibration specific to one of the tunneling pathways, the tunneling pathway is “labeled” and the interference between tunneling pathways is lost. We discuss types of molecules and optical‐spectroscopy experiments which could allow the observation of this effect.
The double slit interference experiment has been famously described by Richard Feynman as containing the "only mystery of quantum mechanics". The history of quantum mechanics is intimately linked with the discovery of the dual nature of matter and radiation. While the double slit experiment for light is easily undertsood in terms of its wave nature, the very same experiment for particles like the electron is somewhat more difficult to comprehend. By the 1920s it was firmly established that electrons have a wave nature. However, for a very long time, most discussions pertaining to interference experiments for particles were merely gedanken experiments. It took almost six decades after the establishment of its wave nature to carry out a 'double slit interference' experiment for electrons. This set the stage for interference experiments with larger particles. In the last decade there has been spectacular progress in matter-wave interefernce experiments. Today, molecules with over a hundred atoms can be made to interfere. In the following we discuss some of these exciting developments which probe new regimes of Nature, bringing us closer to the heart of quantum mechanics and its hidden mysteries.
An atomic interferometer based on a Young's-type double-slit arrangement has been demonstrated. A supersonic beam of metastable helium atoms passes through a 2-\ensuremath{\mu}m-wide slit in a thin gold foil. This transversely coherent beam impinges on a second microfabricated transmission structure, consisting of two 1-\ensuremath{\mu}m-wide slits at a lateral distance of 8 \ensuremath{\mu}m. This double slit defines two possible paths on which the atoms can reach the detector slit. The good visibility of the observed fringes should make it possible to measure differential phase shifts in the interferometer of 1/3 rad in less than 10 min.
Young's double-slit interference experiment is central to quantum mechanics. While it has been demonstrated that an array of atoms can produce interference in light, it is a fundamental question to ask whether a single atom can act as a double slit when prepared in a superposition of two separate positions. Cohen-Tannoudji et al. [Proceedings of the Tenth International Conference on Laser Spectroscopy, edited by M. Ducloy, E. Giacobino, and G. Camy (World Scientific, Singapore, 1992), pp. 3--14] showed that the cross section of the light scattered by a single atom is independent of the spatial separation. In this work, however, we show that when a single atom tunneling in a double well is coupled to an optical ring cavity, the interference phenomena arise if the tunneling rate is comparable to the cavity linewidth. Being driven by an external laser in the dispersive regime, the field emitted by the atom into the cavity exhibits an interference pattern when varying the double-well spacing. Super-Poissonian bunched light can also be generated near the destructive interference. Furthermore, we show that the atomic flux of the coherent tunneling motion generates directional cavity emission, which oscillates for many cycles before the decoherence of the atomic motion and the decay of the cavity photons. Our work opens ways to manipulate photons with controllable external states of atoms for quantum information applications and use cavity light as nondestructive measurements for many-body states of atomic systems.
In quantum mechanics the Young-type double-slit experiment can be performed with electrons either traveling through a double slit or being coherently emitted from two inversion symmetric molecular sites. In the latter one the valence photoionization cross sections of homonuclear diatomic molecules were predicted to oscillate over kinetic energy almost 50 years ago. Beyond the direct proof of the oscillatory behavior of these photoionization cross sections σ, we show that the angular distribution of the emitted electrons reveals hitherto unexplored information on the relative phase shift between the corresponding partial waves through two-center interference patterns.