We demonstrate few-charge occupation of electron and hole quantum dots in silicon via charge sensing. We have fabricated quantum dot (QD) devices in a silicon metal-oxide-semiconductor heterostructure comprising a single-electron transistor next to a single-hole transistor. Both QDs can be tuned to simultaneously sense charge transitions of the other one. We further detect the few-electron and few-hole regimes in the QDs of our device by active charge sensing.

Thijs van den Berg On January 22, 1984, in the break of the third quarter of the NFL's seventeenth Super Bowl, Apple Computer Incorporated aired for the first time the now famous "1984" commercial for its new, Macintosh computer. 1 Needing a commercial winner and increasingly feeling the pressure of IBM, Apple banked its future on the success of Macintosh and the commercial that introduced it to the public. This article argues that Apple's choice to refer to Orwell's dystopian novel Nineteen Eighty-Four (1949) in order to sell computers was informed by more than a lucky coincidence of dates. Rather, the "1984" commercial was to a large extent prompted by the poetics of dystopian discourse. By engaging with Orwell's classic fiction Apple's advertisement was able to activate paradigms of spatial coherency and subversion that are associated with utopian and dystopian constructions, and so effectively managed the commercial space into which Macintosh could emerge. Macintosh and Product Placement: The First iCommodity In 1984, several computer manufacturers were converging from different backgrounds to compete in the relatively new market of what was variously referred to as the home-, personal-or microcomputer. For example, Apple had jumpstarted its business from an electronics and hobbyist background, and sought to expand on its first commercial success, the Apple II. By contrast, IBM had expanded its traditional bigiron, mainframe computer business by introducing the IBM PC for end-users. Meanwhile, Commodore and Sinclair had developed from established calculator manufacturers to produce inexpensive home computers. In this complex and crowded emerging market, IBM had so far been the most successful competitor. Although comparatively late to realise the potential of the microcomputer, by the mid-1980s IBM had ensured that its PC was the dominant computing paradigm for consumers. It was into this turbulent and IBM-dominated marketplace that Apple introduced Macintosh. Apple's decision to quote what is perhaps the most canonical example of dystopian discourse appears to have been inspired by the company's sales strategy for its new Macintosh computer. Macintosh, like so many of Apple's subsequent products, relied to a large extent on the idea that it offered a unique sales alternative to the computing mainstream (i.e. the IBM PC). And certainly this claim was to a degree justified in the case of the Macintosh. As with its upscale sister the Lisa, Apple's Macintosh shipped with a mouse and the System 1.0 operating software, thus introducing pointing devices and graphical user interfaces to ordinary consumers and giving them an alternative to commandline-only microcomputers. However, alongside these innovations, Apple continued to use 'off-the-shelf" parts for the Macintosh so that its 'unique' design shared a large technical base with competing devices. For example, Macintosh was built up around Motorola's 68000 processor architecture, which gave the machine a powerful family connection with, for example, the Commodore...

We consider a two dimensional semiconductor with carriers subject to spinorbit interactions and scattered by randomly distributed magnetic impurities. We solve the time-dependent Schrödinger equation to investigate the relationship between the geometrical properties of the wavefunction and the system's spin dependent transport properties. Even in the absence of localized states, interference effects modify the carrier diffusion, as revealed by the appearance of power laws dependent on the impurity concentration. For stronger disorder, we find a localization transition characterized by a fractal wavefunction and enhanced spin transport.

Two denizens of wilmott.com document their quest to win a data mining contest that required estimating the probability of a binary response variable given 3,751 training samples described on 1,776 dimensions. The contest's log-loss scoring metric provided strong incentives for high-confidence estimates but also strong penalties for over-confident estimates -a pay-off structure also found in strategic investment decisions. The contest offered a low-risk environment for learning in which the only thing we could lose was our dignity, not our capital. We delved into the combined effects of the curse of dimensionality and small sample sizes on the geometries of subregions in a high-D space. We created methods to test if a given projection or sub-region was statistically useful for classifying a data point. This work illustrated five key lessons and many issues associated with data mining and statistical estimation in the era of "Big Data".