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

arXiv:1504.06811 · Physical Review Letters

Observation of Bloch Oscillations in Molecular Rotation

Johannes Floß, Andrei Kamalov, Ilya Sh. Averbukh, P. H. Bucksbaum

Published Nov 11, 2015• 41 citations
arXivHTMLPDF

Abstract

We report the observation of rotational Bloch oscillations in a gas of nitrogen molecules kicked by a periodic train of femtosecond laser pulses. A controllable detuning from the quantum resonance creates an effective accelerating potential in angular momentum space, inducing Bloch-like oscillations of the rotational excitation. These oscillations are measured via the temporal modulation of the refractive index of the gas. Our results introduce room-temperature laser-kicked molecules as a new laboratory for studies of localization phenomena in quantum transport.

DOI
10.1103/physrevlett.115.203002

Related papers

Anderson localization in laser-kicked molecules

Johannes Floß, Shmuel Fishman, Ilya Sh. Averbukh

The paper explores the prospects of observing the phenomenon of dynamical Anderson localization via nonresonant Raman-type rotational excitation of molecules by periodic trains of short laser pulses. We define conditions for such an experiment and show that current femtosecond technology used for nonadiabatic laser alignment of linear molecules is sufficient for this task. Several observables which can serve as indicators for Anderson localization are suggested for measurement, and the influence of experimental limitations imposed by the laser intensity noise, finite pulse duration, limited number of pulses in a train, and thermal effects is analyzed.

Physical Review A•Aug 30, 2013•30 citations

Collision effects and the quantum-to-classical transition in a periodically kicked molecular rotor

A. Espaignol, Franck Billard, E. Hertz +5 more

Purely quantum phenomena such as dynamical localization (DL) can be observed in a molecular rotor subjected to a periodic train of short and intense laser pulses in the gas phase. Using requantized Classical Molecular Dynamics Simulations, we investigate the impact of collisional effects for O2 molecules. We consider different trains of kicks for which the system exhibits quantum resonance, DL, or Bloch oscillations under collision-free conditions. Within achievable experimental conditions, we demonstrate that, as the gas pressure increases, all the dynamics become progressively similar, leading to a quantum-to-classical transition. We study how decoherence induced by intermolecular collisions reduces the quantum interferences through loss of memory. These findings pave the way for future experimental investigations and further theoretical studies on the influence of dissipation on quantum effects in rotational dynamics.

Physical Review A•Aug 5, 2026•0 citations

Anderson localisation in laser kicked molecules

Johannes Floß, Shmuel Fishman, Ilya Sh. Averbukh

The paper explores the prospects of observing the phenomenon of dynamical Anderson localisation via non-resonant Raman-type rotational excitation of molecules by periodic trains of short laser pulses. We define conditions for such an experiment, and show that current femtosecond technology used for non-adiabatic laser alignment of linear molecules is sufficient for this task. Several observables which can serve as indicator for Anderson localisation are suggested for measurement, and the influence of experimental limitations imposed by laser intensity noise, finite pulse duration, limited number of pulses in a train, and thermal effects is analysed.

arXiv:1305.5995•May 26, 2013•1 citation

Observation and Uses of Position-Space Bloch Oscillations in an Ultracold Gas

Zachary A. Geiger, Kurt Fujiwara, Kevin Singh +8 more

We report the observation and characterization of position-space Bloch oscillations using cold atoms in a tilted optical lattice. While momentum-space Bloch oscillations are a common feature of optical lattice experiments, the real-space center-of-mass dynamics are typically unresolvable. In a regime of rapid tunneling and low force, we observe real-space Bloch oscillation amplitudes of hundreds of lattice sites, in both ground and excited bands. We demonstrate two unique capabilities enabled by tracking of Bloch dynamics in position space: measurement of the full position-momentum phase-space evolution during a Bloch cycle, and direct imaging of the lattice band structure. These techniques, along with the ability to exert long-distance coherent control of quantum gases without modulation, may open up new possibilities for quantum control and metrology.

arXiv:1803.02456•Physical Review Letters•May 24, 2018•73 citations

Angular Bloch oscillations and their applications

Bernd Konrad, Maxim A. Efremov

Abstract To advance inertial navigation, we present the scheme for a compact quantum sensor which is based on the quantum phenomenon of the angular Bloch oscillations and measuring exclusively the angular acceleration of slow external rotation. We study the dynamics of ultra-cold atoms confined in a toroidal trap with a ring-lattice along the azimuth angle, realized with the superposition of two copropagating Laguerre–Gaussian beams. In the presence of external rotation with a small angular acceleration, or a prescribed linear chirp between the two beams, the measured angular momentum of the trapped atoms exhibits a specific periodic behaviour in time, which we call as the angular Bloch oscillations. This quantum phenomenon is shown to be a key element of fruitful applications for (i) an efficient transfer of quantized angular momentum from the light to the atoms by controlling the chirp, and (ii) the direct determination of the angular acceleration of external rotation by measuring the Bloch period.

arXiv:2402.12826•Quantum Science and Technology•Oct 24, 2024•3 citations

Directional spinning of molecules with sequences of femtosecond pulses

Casey Kyle Bloomquist, Sergey Zhdanovich, A. Milner +1 more

We present an analysis of two experimental approaches to controlling the directionality of molecular rotation with ultrashort laser pulses. The two methods are based on the molecular interaction with either a pair of pulses (a ``double-kick'' scheme) or a longer pulse sequence (a ``chiral-pulse-train'' scheme). In both cases, rotational control is achieved by varying the polarization of and the time delay between the consecutive laser pulses. Using the technique of polarization-sensitive resonance-enhanced multiphoton ionization, we show that both methods produce significant rotational directionality. We demonstrate that increasing the number of excitation pulses supplements the ability to control the sense of molecular rotation with quantum-state selectivity, i.e., predominant excitation of a single rotational state. We also demonstrate the ability of both techniques to generate counterrotation of molecular nuclear-spin isomers (here, ortho- and para-nitrogen) and molecular isotopologs (here, ${}^{14}$N${}_{2}$ and ${}^{15}$N${}_{2}$).

arXiv:1208.4345•Physical Review A•Dec 19, 2012•27 citations
We report the observation of rotational Bloch oscillations in a gas of nitrogen molecules kicked by a periodic train of femtosecond laser pulses. A controllable detuning from the quantum resonance creates an effective accelerating potential in angular momentum space, inducing Bloch-like oscillations of the rotational excitation. These oscillations are measured via the temporal modulation of the refractive index of the gas. Our results introduce room-temperature laser-kicked molecules as a new laboratory for studies of localization phenomena in quantum transport.
The paper explores the prospects of observing the phenomenon of dynamical Anderson localization via nonresonant Raman-type rotational excitation of molecules by periodic trains of short laser pulses. We define conditions for such an experiment and show that current femtosecond technology used for nonadiabatic laser alignment of linear molecules is sufficient for this task. Several observables which can serve as indicators for Anderson localization are suggested for measurement, and the influence of experimental limitations imposed by the laser intensity noise, finite pulse duration, limited number of pulses in a train, and thermal effects is analyzed.
Purely quantum phenomena such as dynamical localization (DL) can be observed in a molecular rotor subjected to a periodic train of short and intense laser pulses in the gas phase. Using requantized Classical Molecular Dynamics Simulations, we investigate the impact of collisional effects for O2 molecules. We consider different trains of kicks for which the system exhibits quantum resonance, DL, or Bloch oscillations under collision-free conditions. Within achievable experimental conditions, we demonstrate that, as the gas pressure increases, all the dynamics become progressively similar, leading to a quantum-to-classical transition. We study how decoherence induced by intermolecular collisions reduces the quantum interferences through loss of memory. These findings pave the way for future experimental investigations and further theoretical studies on the influence of dissipation on quantum effects in rotational dynamics.
The paper explores the prospects of observing the phenomenon of dynamical Anderson localisation via non-resonant Raman-type rotational excitation of molecules by periodic trains of short laser pulses. We define conditions for such an experiment, and show that current femtosecond technology used for non-adiabatic laser alignment of linear molecules is sufficient for this task. Several observables which can serve as indicator for Anderson localisation are suggested for measurement, and the influence of experimental limitations imposed by laser intensity noise, finite pulse duration, limited number of pulses in a train, and thermal effects is analysed.
We report the observation and characterization of position-space Bloch oscillations using cold atoms in a tilted optical lattice. While momentum-space Bloch oscillations are a common feature of optical lattice experiments, the real-space center-of-mass dynamics are typically unresolvable. In a regime of rapid tunneling and low force, we observe real-space Bloch oscillation amplitudes of hundreds of lattice sites, in both ground and excited bands. We demonstrate two unique capabilities enabled by tracking of Bloch dynamics in position space: measurement of the full position-momentum phase-space evolution during a Bloch cycle, and direct imaging of the lattice band structure. These techniques, along with the ability to exert long-distance coherent control of quantum gases without modulation, may open up new possibilities for quantum control and metrology.
Abstract To advance inertial navigation, we present the scheme for a compact quantum sensor which is based on the quantum phenomenon of the angular Bloch oscillations and measuring exclusively the angular acceleration of slow external rotation. We study the dynamics of ultra-cold atoms confined in a toroidal trap with a ring-lattice along the azimuth angle, realized with the superposition of two copropagating Laguerre–Gaussian beams. In the presence of external rotation with a small angular acceleration, or a prescribed linear chirp between the two beams, the measured angular momentum of the trapped atoms exhibits a specific periodic behaviour in time, which we call as the angular Bloch oscillations. This quantum phenomenon is shown to be a key element of fruitful applications for (i) an efficient transfer of quantized angular momentum from the light to the atoms by controlling the chirp, and (ii) the direct determination of the angular acceleration of external rotation by measuring the Bloch period.
We present an analysis of two experimental approaches to controlling the directionality of molecular rotation with ultrashort laser pulses. The two methods are based on the molecular interaction with either a pair of pulses (a ``double-kick'' scheme) or a longer pulse sequence (a ``chiral-pulse-train'' scheme). In both cases, rotational control is achieved by varying the polarization of and the time delay between the consecutive laser pulses. Using the technique of polarization-sensitive resonance-enhanced multiphoton ionization, we show that both methods produce significant rotational directionality. We demonstrate that increasing the number of excitation pulses supplements the ability to control the sense of molecular rotation with quantum-state selectivity, i.e., predominant excitation of a single rotational state. We also demonstrate the ability of both techniques to generate counterrotation of molecular nuclear-spin isomers (here, ortho- and para-nitrogen) and molecular isotopologs (here, 14{}^{14}14N2{}_{2}2​ and 15{}^{15}15N2{}_{2}2​).