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

Physical review. B, Condensed matter

Atom transfer in the STM double-well potential during a voltage pulse

P. Budau, M. Grigorescu

Published Mar 15, 1998• 10 citations
Publisher

Abstract

The dynamics of atom transfer in the scanning tunneling microscope double-well potential is investigated using the time-dependent Schr\"odinger equation. The transfer is induced by variable electric fields applied between the surface and the tip. The effects related to the crossing of a resonant bias voltage, when atomic quantum-coherence oscillations between the potential wells may appear, are discussed.

DOI
10.1103/physrevb.57.6313

Related papers

Atom oscillations in the scanning tunneling microscope

M. Grigorescu, P. Budau, N. Cârjan

The atom tunneling across the potential barrier separating the surface and the tip of the scanning tunneling microscope is investigated by semiclassical methods, and by integrating numerically the time-dependent Schr\"odinger equation. It is shown that the barrier crossing is explained by the resonance phenomenon of quantum coherence oscillations, rather than by exponential decay. The occurrence of these resonances at the variation of the bias voltage is studied for the first two isomeric states of a Xe atom in a surface-tip potential of double-well shape. The resonant bias voltages for these two states practically coincide, and at the first common resonance the effect of the environmental temperature is discussed. The results provide a useful frame for understanding the mechanism of atom transfer in scanning tunneling microscopy.

Physical review. B, Condensed matter•Mar 15, 1997•8 citations

Coherent tunneling and quantum coherence oscillations at the atomic level

M. Grigorescu

The evolution of the quantum wave packet describing an atom trapped in the surface-tip junction of the scanning tunneling microscope is investigated by using the time-dependent Schroedinger equation, and by a quasi-classical Hamiltonian approach. The estimates concern a Xe atom in a biased double-well junction potential. The exact treatment shows that quantum coherence oscillations of the metastable ground state may occur at particular resonant values of the bias voltage. The effect of decoherence by partial localization is studied within the quasi-classical frame.

arXiv:0802.2781•Feb 20, 2008•0 citations

Heating-assisted atom transfer inthe scanning tunneling microscope

M. Grigorescu

The effects of a voltage pulse on the localization probability for a Xe atom prepared in a pure state localized on the STM surface at 0 temperature is investigated by numerically integrating the time-dependent Schroedinger equation. In these calculations the environmental interactions are neglected, and voltage pulses of 20 and 7 ns with symmetric triangular and trapezoidal shapes are considered. The atom dynamics at an environmental temperature of 4 K is studied in the frame of a stochastic, non-linear Liouville equation for the density operator. It is shown that the irreversible transfer from surface to tip may be explained by thermal decoherence rather than by the driving force acting during the application of the voltage pulse.

arXiv:physics/9709030•Canadian Journal of Physics•Jan 1, 1998•2 citations

Quantum atom switch: Tunneling of Xe atoms

Juan José Sáenz, N. Garcı́a

Recently Eigler, Lutz, and Rudge [Nature 352, 600 (1991)] have reported a bistable switch that derives its function from the motion of a single Xe atom. It has been shown that this atom can be transferred, in a reversible way, from a scanning-tunneling-microscope tip to a sample by means of a voltage pulse. In this paper we show that the atom transfer process can be understood in terms of a single-atom-tunneling process, while a mechanism similar to the heating-assisted electromigration cannot account for the experimental observations. We find that there is a nonzero probability of atom transfer even at zero applied voltage, i.e., the transfer rate cannot follow a power-law dependence with the applied pulse at small voltages. We present a tunneling model, based on the charge transfer from the metal to the 6s resonance of the Xe atoms, which is consistent with the available experimental data.

Physical review. B, Condensed matter•Mar 15, 1993•25 citations

Article

M. Grigorescu

The quantum dynamics of a Xe atom placed on the STM surfaceis studied considering two important types of nonstationary externalforces. These are the driving forces appearing during the application of avoltage pulse, and the fluctuating forces determined by the coupling to anOhmic environment. The localization probability on the tipduring voltage pulses of 20 and 7 ns with symmetric triangular andtrapezoidal shapes is calculated neglecting the environmental interactions.The results indicate that the atom dynamics in this case is reversible, andafter the pulse the transfer probability is small.The effects of the fluctuating forces produced by the coupling to thesurrounding electrons and surface phonons are studied in a static potential.It is shown that the thermal fluctuations at the environmental temperaturecan lead to irreversible atom tunneling through the potential barrier,described by an exponential decay law.PACS Nos.: 61.16.Di, 73.40.Gk, 05.40.+j

Canadian Journal of Physics•Dec 1, 1998•0 citations

Many-body nonequilibrium effects in all-electric electron spin resonance

José Reina Gálvez, Christoph Wolf, Nicolás Lorente

Motivated by recent developments in measurements of electron spin resonances of individual atoms and molecules with a scanning tunneling microscope (ESR-STM), we study electron transport through an impurity under periodic driving as a function of the transport parameters in a model junction. The model consists of a single-orbital quantum impurity connected to two electrodes via time-dependent hopping terms. The hopping terms are treated at the lowest order in perturbation theory to recover a Lindblad-like quantum master equation with electron transport. As in the experiment, the ESR-STM signal is given by the variation of the long-time DC current with the driving frequency. The density-matrix coherences play an important role in the evaluation of the ESR-STM signal. Electron correlation is included in our impurity mode. The charging energy $U$ has significant influence on the spin dynamics depending on the sign and magnitude of the applied DC bias. Our model allows direct insight into the origin of the ESR signal from the many-body dynamics of the impurity.

arXiv:2303.09944•Physical review. B./Physical review. B•Jun 7, 2023•21 citations
The dynamics of atom transfer in the scanning tunneling microscope double-well potential is investigated using the time-dependent Schr"odinger equation. The transfer is induced by variable electric fields applied between the surface and the tip. The effects related to the crossing of a resonant bias voltage, when atomic quantum-coherence oscillations between the potential wells may appear, are discussed.
The atom tunneling across the potential barrier separating the surface and the tip of the scanning tunneling microscope is investigated by semiclassical methods, and by integrating numerically the time-dependent Schr\"odinger equation. It is shown that the barrier crossing is explained by the resonance phenomenon of quantum coherence oscillations, rather than by exponential decay. The occurrence of these resonances at the variation of the bias voltage is studied for the first two isomeric states of a Xe atom in a surface-tip potential of double-well shape. The resonant bias voltages for these two states practically coincide, and at the first common resonance the effect of the environmental temperature is discussed. The results provide a useful frame for understanding the mechanism of atom transfer in scanning tunneling microscopy.
The evolution of the quantum wave packet describing an atom trapped in the surface-tip junction of the scanning tunneling microscope is investigated by using the time-dependent Schroedinger equation, and by a quasi-classical Hamiltonian approach. The estimates concern a Xe atom in a biased double-well junction potential. The exact treatment shows that quantum coherence oscillations of the metastable ground state may occur at particular resonant values of the bias voltage. The effect of decoherence by partial localization is studied within the quasi-classical frame.
The effects of a voltage pulse on the localization probability for a Xe atom prepared in a pure state localized on the STM surface at 0 temperature is investigated by numerically integrating the time-dependent Schroedinger equation. In these calculations the environmental interactions are neglected, and voltage pulses of 20 and 7 ns with symmetric triangular and trapezoidal shapes are considered. The atom dynamics at an environmental temperature of 4 K is studied in the frame of a stochastic, non-linear Liouville equation for the density operator. It is shown that the irreversible transfer from surface to tip may be explained by thermal decoherence rather than by the driving force acting during the application of the voltage pulse.
Recently Eigler, Lutz, and Rudge [Nature 352, 600 (1991)] have reported a bistable switch that derives its function from the motion of a single Xe atom. It has been shown that this atom can be transferred, in a reversible way, from a scanning-tunneling-microscope tip to a sample by means of a voltage pulse. In this paper we show that the atom transfer process can be understood in terms of a single-atom-tunneling process, while a mechanism similar to the heating-assisted electromigration cannot account for the experimental observations. We find that there is a nonzero probability of atom transfer even at zero applied voltage, i.e., the transfer rate cannot follow a power-law dependence with the applied pulse at small voltages. We present a tunneling model, based on the charge transfer from the metal to the 6s resonance of the Xe atoms, which is consistent with the available experimental data.
The quantum dynamics of a Xe atom placed on the STM surfaceis studied considering two important types of nonstationary externalforces. These are the driving forces appearing during the application of avoltage pulse, and the fluctuating forces determined by the coupling to anOhmic environment. The localization probability on the tipduring voltage pulses of 20 and 7 ns with symmetric triangular andtrapezoidal shapes is calculated neglecting the environmental interactions.The results indicate that the atom dynamics in this case is reversible, andafter the pulse the transfer probability is small.The effects of the fluctuating forces produced by the coupling to thesurrounding electrons and surface phonons are studied in a static potential.It is shown that the thermal fluctuations at the environmental temperaturecan lead to irreversible atom tunneling through the potential barrier,described by an exponential decay law.PACS Nos.: 61.16.Di, 73.40.Gk, 05.40.+j
Motivated by recent developments in measurements of electron spin resonances of individual atoms and molecules with a scanning tunneling microscope (ESR-STM), we study electron transport through an impurity under periodic driving as a function of the transport parameters in a model junction. The model consists of a single-orbital quantum impurity connected to two electrodes via time-dependent hopping terms. The hopping terms are treated at the lowest order in perturbation theory to recover a Lindblad-like quantum master equation with electron transport. As in the experiment, the ESR-STM signal is given by the variation of the long-time DC current with the driving frequency. The density-matrix coherences play an important role in the evaluation of the ESR-STM signal. Electron correlation is included in our impurity mode. The charging energy UUU has significant influence on the spin dynamics depending on the sign and magnitude of the applied DC bias. Our model allows direct insight into the origin of the ESR signal from the many-body dynamics of the impurity.