第一个例子:D. Gammon, E. S. Snow, B. V. Shanabrook, D. S.Katzer, and D. Park,
Phys. Rev. Lett.76,3005 (1996).
In this Letter we describe thepolarization dependence of the optical spectra of single naturallyformed GaAs quantum dots. Most previous optical studies of quantumdots (QDs) have probed large ensembles which have led toinhomogeneous broadening of the spectral features. However, recentlyseveral groups have shown that it is possible to study single QDswith photoluminescence (PL) either by reducing the size of thesample, [1] by cathodoluminescence [2,3], or by reducing the size ofthe laser spot on the sample through microscopic [4,5] or opticalnear-field techniques [6]. Here we use a similar technique whereby we combine highspatial and spectral resolution optics with excitation spectroscopyto study in detail the spectrum of a single QD [7].
第二个例子:FrankWilczek,Phys. Rev. Lett. 111, 250402 (2013).
Recently there has been considerableinterest in the possibility of spontaneous breaking of timetranslation symmetry \tau [1]- [5]. Here I bring in ideas fromsuperfluidity which offer additional perspectives and widen thepossibilities significantly.
While Grover’s algorithm wasoriginally proposed as a digital, or discrete-time, algorithm [1],Farhi and Gutmann formulated it as an equivalent analog, orcontinuous time, algorithm [2]. We use Childs and Goldstone’snotation and interpretation of this algorithm [3] as a quantumrandomly walking particle on the complete graph of N vertices, anexample of which is shown in Fig. 1.
Yu. M. Gal'perin, V. I. Kozub, and B. Z. Spivak, Stability of the nonequilibrium states of a superconducto with a finite difference between the populations of the electron and hole like spectral branches, Zj. Eksp. Theor. Fiz. 1981.
1. Introduction
The purpose of the present communication is to show that the nonequlibirum state of a superconductor is unstable against order parameter fluctuations.