文章来源:未知 文章作者:meng 发布时间:2010-01-11 00:27 字体: [ ]  进入论坛

In an important first for a promising1 new technology, scientists have used a quantum量子 computer to calculate the precise energy of molecular2分子的 hydrogen. This groundbreaking开创性的 approach to molecular simulations could have profound implications not just for quantum chemistry, but also for a range of fields from cryptography密码学 to materials science. "One of the most important problems for many theoretical chemists is how to execute exact simulations of chemical systems," says author Alán Aspuru-Guzik, assistant professor of chemistry and chemical biology at Harvard University. "This is the first time that a quantum computer has been built to provide these precise calculations."

The work, described this week in Nature Chemistry, comes from a partnership3 between Aspuru-Guzik's team of theoretical chemists at Harvard and a group of experimental physicists4 led by Andrew White at the University of Queensland in Brisbane, Australia. Aspuru-Guzik's team coordinated5 experimental design and performed key calculations, while his partners in Australia assembled the physical "computer" and ran the experiments.

"We were the software guys," says Aspuru-Guzik, "and they were the hardware guys."

While modern supercomputers can perform approximate大概的,近似的 simulations of simple molecular systems, increasing the size of the system results in an exponential指数的 increase in computation time. Quantum computing6 has been heralded通报,宣布 for its potential to solve certain types of problems that are impossible for conventional computers to crack.

Rather than using binary8二元的 bits labeled as "zero" and "one" to encode data, as in a conventional computer, quantum computing stores information in qubits量子比特, which can represent both "zero" and "one" simultaneously9. When a quantum computer is put to work on a problem, it considers all possible answers by simultaneously arranging its qubits into every combination of "zeroes" and "ones."

Since one sequence of qubits can represent many different numbers, a quantum computer would make far fewer computations than a conventional one in solving some problems. After the computer's work is done, a measurement of its qubits provides the answer.

"Because classical computers don't scale efficiently10, if you simulate anything larger than four or five atoms -- for example, a chemical reaction, or even a moderately complex molecule11 -- it becomes an intractable棘手的,难治的 problem very quickly," says author James Whitfield, research assistant in chemistry and chemical biology at Harvard. "Approximate computations of such systems are usually the best chemists can do."

Aspuru-Guzik and his colleagues confronted遭遇,面对 this problem with a conceptually elegant高雅的,讲究的 idea.

"If it is computationally too complex to simulate a quantum system using a classical computer," he says, "why not simulate quantum systems with another quantum system?"

Such an approach could, in theory, result in highly precise calculations while using a fraction部分,稍微 the resources of conventional computing.

While a number of other physical systems could serve as a computer framework, Aspuru-Guzik's colleagues in Australia used the information encoded in two entangled12卷入的,被缠住的 photons to conduct their hydrogen molecule simulations. Each calculated energy level was the result of 20 such quantum measurements, resulting in a highly precise measurement of each geometric几何学的 state of molecular hydrogen.

"This approach to computation represents an entirely13 new way of providing exact solutions to a range of problems for which the conventional wisdom is that approximation接近,近似值 is the only possibility," says Aspuru-Guzik.

Ultimately, the same quantum computer that could transform Internet cryptography could also calculate the lowest energy conformations of molecules14 as complex as cholesterol胆固醇.


1 promising BkQzsk     
  • The results of the experiments are very promising.实验的结果充满了希望。
  • We're trying to bring along one or two promising young swimmers.我们正设法培养出一两名有前途的年轻游泳选手。
2 molecular mE9xh     
  • The research will provide direct insight into molecular mechanisms.这项研究将使人能够直接地了解分子的机理。
  • For the pressure to become zero, molecular bombardment must cease.当压强趋近于零时,分子的碰撞就停止了。
3 partnership NmfzPy     
  • The company has gone into partnership with Swiss Bank Corporation.这家公司已经和瑞士银行公司建立合作关系。
  • Martin has taken him into general partnership in his company.马丁已让他成为公司的普通合伙人。
4 physicists 18316b43c980524885c1a898ed1528b1     
物理学家( physicist的名词复数 )
  • For many particle physicists, however, it was a year of frustration. 对于许多粒子物理学家来说,这是受挫折的一年。 来自英汉非文学 - 科技
  • Physicists seek rules or patterns to provide a framework. 物理学家寻求用法则或图式来构成一个框架。
5 coordinated 72452d15f78aec5878c1559a1fbb5383     
  • The sound has to be coordinated with the picture. 声音必须和画面协调一致。
  • The numerous existing statutes are complicated and poorly coordinated. 目前繁多的法令既十分复杂又缺乏快调。 来自英汉非文学 - 环境法 - 环境法
6 computing tvBzxs     
  • to work in computing 从事信息处理
  • Back in the dark ages of computing, in about 1980, they started a software company. 早在计算机尚未普及的时代(约1980年),他们就创办了软件公司。
7 heralded a97fc5524a0d1c7e322d0bd711a85789     
v.预示( herald的过去式和过去分词 );宣布(好或重要)
  • The singing of the birds heralded in the day. 鸟鸣报晓。 来自《简明英汉词典》
  • A fanfare of trumpets heralded the arrival of the King. 嘹亮的小号声宣告了国王驾到。 来自《简明英汉词典》
8 binary jybzWZ     
  • Computers operate using binary numbers.计算机运行运用二进位制。
  • Let us try converting the number itself to binary.我们试一试,把这个数本身变成二进制数。
9 simultaneously 4iBz1o     
  • The radar beam can track a number of targets almost simultaneously.雷达波几乎可以同时追着多个目标。
  • The Windows allow a computer user to execute multiple programs simultaneously.Windows允许计算机用户同时运行多个程序。
10 efficiently ZuTzXQ     
  • The worker oils the machine to operate it more efficiently.工人给机器上油以使机器运转更有效。
  • Local authorities have to learn to allocate resources efficiently.地方政府必须学会有效地分配资源。
11 molecule Y6Tzn     
  • A molecule of water is made up of two atoms of hygrogen and one atom of oxygen.一个水分子是由P妈?f婘??妈?成的。
  • This gives us the structural formula of the molecule.这种方式给出了分子的结构式。
12 entangled e3d30c3c857155b7a602a9ac53ade890     
adj.卷入的;陷入的;被缠住的;缠在一起的v.使某人(某物/自己)缠绕,纠缠于(某物中),使某人(自己)陷入(困难或复杂的环境中)( entangle的过去式和过去分词 )
  • The bird had become entangled in the wire netting. 那只小鸟被铁丝网缠住了。
  • Some military observers fear the US could get entangled in another war. 一些军事观察家担心美国会卷入另一场战争。 来自《简明英汉词典》
13 entirely entirely     
  • The fire was entirely caused by their neglect of duty. 那场火灾完全是由于他们失职而引起的。
  • His life was entirely given up to the educational work. 他的一生统统献给了教育工作。
14 molecules 187c25e49d45ad10b2f266c1fa7a8d49     
分子( molecule的名词复数 )
  • The structure of molecules can be seen under an electron microscope. 分子的结构可在电子显微镜下观察到。
  • Inside the reactor the large molecules are cracked into smaller molecules. 在反应堆里,大分子裂变为小分子。
15 cholesterol qrzzV     
  • There is cholesterol in the cell of body.人体细胞里有胆固醇。
  • They are determining the serum-protein and cholesterol levels.他们正在测定血清蛋白和胆固醇的浓度。
TAG标签: quantum hydrogen molecular