scholarly journals Study on Mechanisms of Photon-Induced Material Removal on Silicon at Atomic and Close-to-Atomic Scale

2021 ◽  
Author(s):  
Peizhi Wang ◽  
Jinshi Wang ◽  
Fengzhou Fang
Keyword(s):  
Surface Modification ◽  
Excited States ◽  
Linear Dependence ◽  
Material Removal ◽  
Open Quantum Systems ◽  
Quantum Systems ◽  
Atomic Scale ◽  
New Approach ◽  
Von Neumann ◽  
Photon Irradiation

AbstractThis paper presents a new approach for material removal on silicon at atomic and close-to-atomic scale assisted by photons. The corresponding mechanisms are also investigated. The proposed approach consists of two sequential steps: surface modification and photon irradiation. The back bonds of silicon atoms are first weakened by the chemisorption of chlorine and then broken by photon energy, leading to the desorption of chlorinated silicon. The mechanisms of photon-induced desorption of chlorinated silicon, i.e., SiCl2 and SiCl, are explained by two models: the Menzel–Gomer–Redhead (MGR) and Antoniewicz models. The desorption probability associated with the two models is numerically calculated by solving the Liouville–von Neumann equations for open quantum systems. The calculation accuracy is verified by comparison with the results in literatures in the case of the NO/Pt (111) system. The calculation method is then applied to the cases of SiCl2/Si and SiCl/Si systems. The results show that the value of desorption probability first increases dramatically and then saturates to a stable value within hundreds of femtoseconds after excitation. The desorption probability shows a super-linear dependence on the lifetime of excited states.

scholarly journals Parameter-free driven Liouville-von Neumann approach for time-dependent electronic transport simulations in open quantum systems

2017 ◽  
Vol 146 (9) ◽  
pp. 092331 ◽  
Author(s):  
Tamar Zelovich ◽  
Thorsten Hansen ◽  
Zhen-Fei Liu ◽  
Jeffrey B. Neaton ◽  
Leeor Kronik ◽  
...  
Keyword(s):  
Electronic Transport ◽  
Open Quantum Systems ◽  
Quantum Systems ◽  
Time Dependent ◽  
Von Neumann ◽  
Open Quantum

scholarly journals Effects of symmetry breaking of the structurally-disordered Hamiltonian ensembles on the anisotropic decoherence

2021 ◽  
Author(s):  
Hong-Bin Chen
Keyword(s):  
Probability Distribution ◽  
Symmetry Breaking ◽  
Canonical Form ◽  
Open Quantum Systems ◽  
Dynamical Behavior ◽  
Structural Disorder ◽  
Quantum Systems ◽  
New Approach ◽  
Pure Dephasing ◽  
Different Types

Abstract It is commonly known that the dephasing in open quantum systems is due to the establishment of bipartite correlations with an environment. Recently, a new approach of average over disordered Hamiltonian ensemble is developed and shown to capable of describing both the incoherent dynamical behavior and the nonclassicality of dynamical processes. Here we further extend the approach of Hamiltonian ensemble in the canonical form to the realm of structural disorder. Under the separation of the probability distribution within the Hamiltonian ensemble, the geometrical structural is easily visualized and can be characterized according to the degree of symmetry. We demonstrate four degrees and investigate the effects of different types of symmetry breaking on the incoherent dynamics. With these effects, we obtain rather general master equations, going beyond the previous frameworks of pure dephasing or isotropic depolarization. The practicality of the Hamiltonian ensemble and the theory of process nonclassicality is significantly enhanced.

scholarly journals Assessment of weak-coupling approximations on a driven two-level system under dissipation

2021 ◽  
Author(s):  
Wallace Teixeira ◽  
Fernando L Semiao ◽  
Jani Tuorila ◽  
Mikko Möttönen
Keyword(s):  
Weak Coupling ◽  
Open Quantum Systems ◽  
Cutoff Frequency ◽  
Energy Shift ◽  
Quantum Systems ◽  
Lindblad Equation ◽  
Von Neumann ◽  
Open Quantum ◽  
Perturbative Methods ◽  
Perturbative Method

Abstract The standard weak-coupling approximations associated to open quantum systems have been extensively used in the description of a two-level quantum system, qubit, subjected to relatively weak dissipation compared with the qubit frequency. However, recent progress in the experimental implementations of controlled quantum systems with increased levels of on-demand engineered dissipation has motivated precision studies in parameter regimes that question the validity of the approximations, especially in the presence of time-dependent drive fields. In this paper, we address the precision of weak-coupling approximations by studying a driven qubit through the numerically exact and non-perturbative method known as the stochastic Liouville-von Neumann equation with dissipation. By considering weak drive fields and a cold Ohmic environment with a high cutoff frequency, we use the Markovian Lindblad master equation as a point of comparison for the SLED method and study the influence of the bath-induced energy shift on the qubit dynamics. We also propose a metric that may be used in experiments to map the regime of validity of the Lindblad equation in predicting the steady state of the driven qubit. In addition, we study signatures of the well-known Mollow triplet and observe its meltdown owing to dissipation in an experimentally feasible parameter regime of circuit electrodynamics. Besides shedding light on the practical limitations of the Lindblad equation, we expect our results to inspire future experimental research on engineered open quantum systems, the accurate modeling of which may benefit from non-perturbative methods.

Relaxation of interacting open quantum systems

2018 ◽  
Vol 189 (05) ◽  
Author(s):  
Vladislav Yu. Shishkov ◽  
Evgenii S. Andrianov ◽  
Aleksandr A. Pukhov ◽  
Aleksei P. Vinogradov ◽  
A.A. Lisyansky
Keyword(s):  
Open Quantum Systems ◽  
Quantum Systems ◽  
Open Quantum
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