Bloch oscillations in uniform magnetic and electric fields

1987 ◽  
Vol 98 (2) ◽  
pp. 145-157 ◽  
Author(s):  
A. Jannussis ◽  
E. Skuras ◽  
V. Papatheou
Keyword(s):  
Electric Fields ◽  
Bloch Oscillations

scholarly journals Polaron dynamics of Bloch–Zener oscillations in an extended Holstein model

2021 ◽  
Vol 23 (12) ◽  
pp. 123020
Author(s):  
Zhongkai Huang ◽  
Alejandro D Somoza ◽  
Cheng Peng ◽  
Jin Huang ◽  
Maolin Bo ◽  
...  
Keyword(s):  
Wave Packet ◽  
Electric Fields ◽  
Quantum Electrodynamics ◽  
Band Gaps ◽  
Harmonic Oscillators ◽  
Von Neumann Entropy ◽  
Bloch Oscillations ◽  
Von Neumann ◽  
Recent Developments ◽  
Master Equation Approach

Abstract Recent developments in qubit engineering make circuit quantum electrodynamics devices promising candidates for the study of Bloch oscillations (BOs) and Landau–Zener (LZ) transitions. In this work, a hybrid circuit chain with alternating site energies under external electric fields is employed to study Bloch–Zener oscillations (BZOs), i.e. coherent superpositions of BOs and LZ transitions. We couple each of the tunable qubits in the chain to dispersionless optical phonons and build an extended Holstein polaron model with the purpose of investigating vibronic effects in the BZOs. We employ an extension of the Davydov ansatz in combination with the Dirac–Frenkel time-dependent variational principle to simulate the dynamics of the qubit chain under the influence of high-frequency quantum harmonic oscillators. Band gaps emerge due to energy differences in site energies at alternating qubit sites, and are shown to play key roles in tuning band structures and time periodic reconstructions of the wave patterns. In the absence of qubit–phonon interactions, the qubits undergo either standard BZOs or breathing modes, depending on whether the initial wave packet is formed by a broad or narrow Gaussian wave packet, respectively. The BZOs can get localized in space if the band gaps are sufficiently large. In the presence of qubit–phonon coupling, the periodic behavior of BZOs can be washed out and undergo dynamic localization. The influence of an ohmic bath on the dynamics of BZOs is investigated by means of a Markovian master equation approach. Finally, we calculate the von Neumann entropy as a measure of the entanglement between qubits and phonons.

scholarly journals Effect of Strong Electric Fields on Material Responses: The Bloch Oscillation Resonance in High Field Conductivities

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1070 ◽  
Author(s):  
Satyvir Singh ◽  
Marco Battiato
Keyword(s):  
Steady State ◽  
Electric Fields ◽  
High Field ◽  
Transient Behavior ◽  
Analytic Solutions ◽  
Boltzmann Transport ◽  
Bloch Oscillations ◽  
Bloch Oscillation ◽  
Low Field ◽  
Strong Electric Fields

In this paper, we investigated the effect of strong electric fields on material responses and the Bloch oscillation resonance in high field conductivities. For this purpose, a high-order accurate explicit modal discontinuous Galerkin (DG) solver is employed for solving the quantum Boltzmann transport equation (BTE) in the context of electron transport at nanoscales under strongly out-of-equilibrium conditions. Here, we study the transient behavior and the convergence of a steady-state response to an external oscillating electric field switched on at time zero. We first benchmark our numerical results with known analytic steady-state responses at low fields. The computational results show that the present DG scheme is in excellent agreement with analytic solutions over the whole range of parameters and to an extremely high precision, allowing us to achieve good agreement even for the fifth-order response at low fields. We then extend the method to strong electric fields and show how the responses are deviated from the low-field ones and the transition to a dampened Bloch oscillation regime. Most importantly, we report the observation of a new regime induced by the resonance between the standard low-field response and Bloch oscillations.

scholarly journals Quantum walks in weak electric fields and Bloch oscillations

2020 ◽  
Vol 101 (6) ◽  
Author(s):  
Pablo Arnault ◽  
Benjamin Pepper ◽  
A. Pérez
Keyword(s):  
Electric Fields ◽  
Quantum Walks ◽  
Bloch Oscillations

BLOCH ELECTRON DYNAMICS IN SPATIALLY HOMOGENEOUS ELECTRIC FIELDS

1998 ◽  
Vol 09 (01) ◽  
pp. 223-250 ◽  
Author(s):  
G. J. IAFRATE ◽  
J. P. REYNOLDS ◽  
J. HE ◽  
J. B. KRIEGER
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Quantum Dynamics ◽  
Electron Dynamics ◽  
Bloch Oscillations ◽  
Electric Field Effects ◽  
Bloch Electron ◽  
Field Effects ◽  
Arbitrary Strength ◽  
Spatially Homogeneous

The theory of Bloch electron dynamics in spatially homogeneous electric fields of arbitrary strength and time dependence is presented. In the formalism, the electric field is described through the use of the vector potential, and the instantaneous eigenstates of the Hamiltonian are used as basis stated to depict the Bloch dynamics and quantum properties. This approach leads to a natural indication of high- and low-filed limits, and allows for the inclusion of general band-structure effects and multiband coupling in the quantum dynamics. A variety of dc electric field effects, such as Bloch oscillations, Zener tunneling, and localization, and ac electric field effects, such as interband absorption, and phonon-assisted transport, will be discussed.

Control of Metal Alloy Oxidation with Electric Fields

1973 ◽  
Vol 31 ◽  
pp. 164-165
Author(s):  
R. R. Dils ◽  
P. S. Follansbee
Keyword(s):  
Electric Fields ◽  
Oxidation Process ◽  
Base Alloy ◽  
Oxide Surface ◽  
Platinum Electrodes ◽  
Insulating Layer ◽  
Iron Base Alloy ◽  
Alloy Oxidation ◽  
Aluminum Oxide Layer ◽  
And Control

Electric fields have been applied across oxides growing on a high temperature alloy and control of the oxidation of the material has been demonstrated. At present, three-fold increases in the oxidation rate have been measured in accelerating fields and the oxidation process has been completely stopped in a retarding field.The experiments have been conducted with an iron-base alloy, Pe 25Cr 5A1 0.1Y, although, in principle, any alloy capable of forming an adherent aluminum oxide layer during oxidation can be used. A specimen is polished and oxidized to produce a thin, uniform insulating layer on one surface. Three platinum electrodes are sputtered on the oxide surface and the specimen is reoxidized.

Electron-Mirror Microscopic Aspects of Ferroelectric Domains of BaTiO3 And Ca2Sr (C2H5CO2)6

1970 ◽  
Vol 28 ◽  
pp. 478-479
Author(s):  
Teruo Someya ◽  
Jinzo Kobayashi
Keyword(s):  
Surface Layer ◽  
Electric Fields ◽  
Quantitative Study ◽  
Recent Progress ◽  
Ferroelectric Domain ◽  
Resolving Power ◽  
Surface Pattern ◽  
Crystal Surfaces ◽  
One Dimensional ◽  
Ferroelectric Domains

Recent progress in the electron-mirror microscopy (EMM), e.g., an improvement of its resolving power together with an increase of the magnification makes it useful for investigating the ferroelectric domain physics. English has recently observed the domain texture in the surface layer of BaTiO3. The present authors ) have developed a theory by which one can evaluate small one-dimensional electric fields and/or topographic step heights in the crystal surfaces from their EMM pictures. This theory was applied to a quantitative study of the surface pattern of BaTiO3).

Electron Microscope Observations of Magnetic and Electric Effects

1970 ◽  
Vol 28 ◽  
pp. 430-431
Author(s):  
John Silcox
Keyword(s):  
Electron Microscope ◽  
Electric Fields ◽  
Magnetic Image ◽  
Magnetic Effects ◽  
Ferromagnetic Films ◽  
Diffraction Contrast ◽  
Microscope Images ◽  
Electric Effects ◽  
Image Detail

Several aspects of magnetic and electric effects in electron microscope images are of interest and will be discussed here. Clearly electrons are deflected by magnetic and electric fields and can give rise to image detail. We will review situations in ferromagnetic films in which magnetic image effects are the predominant ones, others in which the magnetic effects give rise to rather subtle changes in diffraction contrast, cases of contrast at specimen edges due to leakage fields in both ferromagnets and superconductors and some effects due to electric fields in insulators.

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