英语沙龙：第一个纳米电路（在线收听）

The first nano circuit

IBM makes the tiniest computer part ever.

Even the most optimistic semiconductor researchers say that silicon－based computer chips may only have １５years or so left in them．

After that，it will be impossible to fit any more circuits onto these increasingly minute wafers to power inexorably smaller and smarter computers．Consequently，researchers are determined to figure out how to make complex microprocessors out of other materials．IBM made a significant breakthrough in August when physicists at its Thomas J．Watson Research Center，built the world’s first logic circuit out of a single long carbon molecule called a nanotube．Though the first laptop with nanotubes inside is still a long way off，the IBM invention“was a critical step，”says Phaedon Avouris，a member of the group that created the circuit．

As pliant as silicon has been over the last half－century，carbon nanotubes have some significant advantages．They’re as small as a semiconductor can get，so engineers will be able to pack trillions of them onto a single chip．And since they’re thin and long，like a garden hose，electrons are funneled straight through the circuit ――dramatically cutting down resistance．That results in less heat and less power dissipation than occurs with silicon．

But enormous technical problems remain．For one thing，even today’s average desktop computer would require at least a few million of these circuits，and there are no known methods for producing large numbers of them quickly and efficiently．Equally important is the challenge of connecting a series of individual and disparate logic circuits into microprocessors．And while computers run on three different types of logic circuits ――called And，Not，and Or gates ――IBM’s Not gate is the only type that has yet been created from carbon nanotubes．

The IBM advance is a good start；now engineers have a little more than another decade to finish the job．

第一个纳米电路

IBM造出有史以来最小的计算机零件。

即便最乐观的半导体研究者都说，以硅为原料的计算机芯片或许最多还能存在１５年左右。此后，要在这些晶片上再加进任何电路都是不可能的了：因为晶片越来越小，晶片驱动的计算机也越来越小，越来越智能化。因此，科学家决心研究出如何用其他材料制造复杂的微处理器。８月份，IBM取得重大突破。该公司托马斯·沃森研究中心的物理学家造出全世界第一个以纳米管（一个长长的碳分子）为原料的逻辑电路。创造出这个电路的小组成员费宗·瓦武里斯说，尽管要造出有纳米管的电脑还有很长一段路要走，IBM的这项发明仍然“是关键的一步”。

尽管硅在过去半个世纪里用途广泛，但碳纳米管拥有某些明显优势。半导体能有多小它们就能多小；因此，工程师能够把数以兆计的碳纳米管安在一块芯片上。此外，由于它们像水管一样又细又长，电子可以直接穿过电路：这大大减少了阻力，从而比用硅做原料时耗能少，产生的热也少。

但是，仍然存在大量技术问题。例如，即使今天普通的桌上电脑也需要至少几百万个这种电路，目前人们还不知道怎样快速有效地大批量生产它们。同样重要的是，如何把一系列单个分离的逻辑电路连接成微处理器。计算机在三种不同的逻辑电路上运行，这三种电路称作And，Not和Or 。IBM的Not是目前惟一利用碳纳米管制造出来的逻辑电路。

IBM的进展开了一个好头。如今，工程师们还有十几年的时间来完成这项工作。