We prove a robust extension of the quantum adiabatic theorem. The theorem applies to systems that have resonances instead of bound states, and to systems for which just an approximation to a bound state is known. To demonstrate the theorem's usefulness in a concrete situation, we apply it to shape resonances.
We present generalized adiabatic theorems for closed and open quantum systems that can be applied to slow modulations of rapidly varying fields, such as oscillatory fields that occur in optical experiments and light induced processes. The generalized adiabatic theorems show that a sufficiently slow modulation conserves the dynamical modes of time dependent reference Hamiltonians. In the limiting case of modulations of static fields, the standard adiabatic theorems are recovered. Applying these results to periodic fields shows that they remain in Floquet states rather than in energy eigenstates…
The evolution of a driven quantum system is said to be adiabatic whenever the state of the system stays close to an instantaneous eigenstate of its time-dependent Hamiltonian. The celebrated quantum adiabatic theorem ensures that such pure state adiabaticity can be maintained with arbitrary accuracy, provided one chooses a small enough driving rate. Here, we extend the notion of quantum adiabaticity to closed quantum systems initially prepared at finite temperature. In this case adiabaticity implies that the (mixed) state of the system stays close to a quasi-Gibbs state diagonal in the basis o…
Adiabatensätze mit und ohne Spektrallückenbedingung
在这项工作中,我们推广了一些以前已知的绝热定理的情况下,在Banach空间中的非酉演变。我们证明了具有一致间隙条件的绝热定理(推广了Abou Salem的一个定理)、具有非一致间隙条件的绝热定理(推广了Kato的一个定理)以及不具有间隙条件的定性和定量绝热定理(推广了Avron和Elgart以及Teufel的定理)。此外,我们给出了Nenciu的一个高阶绝热定理的推广形式。在所有这些绝热定理中,所考虑的谱值不需要位于虚轴上,并且在具有谱间隙条件的绝热定理和谱的高阶紧致子集的绝热定理中是充分的(特别地,这些子集不需要由本征值组成)。我们探讨的强度绝热定理在许多例子。特别是,我们表明,本工作的定理比以前已知的定理更一般。这项工作于2010年10月完成,并在斯图加特大学数学系作为毕业论文提交。因此,在此期间(2011年6月)出现的Avron,Fraas,Graf und Grech的最新结果不在此考虑。然而,我们指出,本工作的定理是更普遍的比相应的定理Avron,Fraas,格拉夫和Grech -除了绝热定理的高阶这是没有逻辑关系的绝热定理的高阶Avron,Fraas,格拉夫和Grech。我们即将在一篇文章中收集目前工作中最重要的定理,并将很快将其上传到arXiv。
It has been recently reported that classical systems have speed limit for state evolution, although such a concept of speed limit had been considered to be unique to quantum systems. Owing to the speed limit for classical system, the lower bound for calculation time of simulated annealing with desired calculation accuracy can be derived. However, such a lower bound does not work as a criterion for completion of calculation in a practical time. In this paper, we derive an inequality for classical system analogous to the quantum adiabatic theorem that gives calculation time for an accuracy-guara…
Propagators weakly associated to a family of Hamiltonians and the adiabatic theorem for the Landau Hamiltonian with a time-dependent Aharonov-Bohm flux
We prove an adiabatic theorem for the Landau-Pekar equations. This allows us to derive new results on the accuracy of their use as effective equations for the time evolution generated by the Fröhlich Hamiltonian with large coupling constant $α$. In particular, we show that the time evolution of Pekar product states with coherent phonon field and the electron being trapped by the phonons is well approximated by the Landau-Pekar equations until times short compared to $α^2$.