Australian and American physicists have built a working transistor from a single phosphorus atom embedded in a silicon crystal.
The group of physicists, based at theUniversity of New South Wales andPurdue University, said they had laid the groundwork for a futuristic quantum computer that might one day function in a nanoscale world and would be orders of magnitude smaller and quicker than today’s silicon-based machines.
In contrast to conventional computers that are based on transistors with distinct “on” and “off” or “1” and “0” states, quantum computers are built from devices called qubits that exploit the quirky properties of quantum mechanics. Unlike a transistor, a qubit can represent a multiplicity of values simultaneously.
That might make it possible to factor large numbers more quickly than with conventional machines — thereby undermining modern data-scrambling systems that are the basis of electronic commerce and data privacy. Quantum computers might also make it possible to simulate molecular structures with great speed, an advance that holds promise for designing new drugs and other kinds of materials.
“Their approach is extremely powerful,” said Andreas Heinrich, an I.B.M. physicist. “This is at least a 10-year effort to make very tiny electrical wires and combine them with the placement of a phosphorus atom exactly where they want them.”
He said the research was a significant step toward making a functioning quantum computing system. However, whether quantum computing will ever be harnessed for useful tasks remains uncertain, and the researchers also noted that their work demonstrated the fundamental limits that today’s computers would be able to shrink to.
“It shows that Moore’s Law can be scaled toward atomic scales in silicon,” said Gerhard Klimeck, professor of electrical and computer engineering at Purdue. Moore’s Law refers to technology improvements by the semiconductor industry that have doubled the number of transistors on a silicon chip roughly every 18 months for the past half century. That has led to accelerating increases in performance and declining prices. “The technologies for classical computing can survive to the atomic scale.”
When Kenneth G. Lieberthal, a China expert at the Brookings Institution, travels to that country, he follows a routine that seems straight from a spy film.
He leaves his cellphone and laptop at home and instead brings “loaner” devices, which he erases before he leaves the United States and wipes clean the minute he returns. In China, he disables Bluetooth and Wi-Fi, never lets his phone out of his sight and, in meetings, not only turns off his phone but also removes the battery, for fear his microphone could be turned on remotely. He connects to the Internet only through an encrypted, password-protected channel, and copies and pastes his password from a USB thumb drive. He never types in a password directly, because, he said, “the Chinese are very good at installing key-logging software on your laptop.”
What might have once sounded like the behavior of a paranoid is now standard operating procedure for officials at American government agencies, research groups and companies that do business in China and Russia — like Google, the State Department and the Internet security giant McAfee. Digital espionage in these countries, security experts say, is a real and growing threat — whether in pursuit of confidential government information or corporate trade secrets.
“If a company has significant intellectual property that the Chinese and Russians are interested in, and you go over there with mobile devices, your devices will get penetrated,” said Joel F. Brenner, formerly the top counterintelligence official in the office of the director of national intelligence.
Theft of trade secrets was long the work of insiders — corporate moles or disgruntled employees. But it has become easier to steal information remotely because of the Internet, the proliferation of smartphones and the inclination of employees to plug their personal devices into workplace networks and cart proprietary information around. Hackers’ preferred modus operandi, security experts say, is to break into employees’ portable devices and leapfrog into employers’ networks — stealing secrets while leaving nary a trace.
When Jeryl Brunner, a writer in Manhattan, was in her 20s, she had a friend who was just the sort of acquaintance people scoop up in their social net when they are young and trying to carve out a life in a new city. The friend was fun, outgoing and stylish, and always up for a night of dancing at Area, or a weekend jaunt to a Neiman Marcus outlet in New Jersey.
But as Ms. Brunner neared 40, the reasons for their spending time together became less clear. “It’s almost like we were in different movies,” said Ms. Brunner, now 46. “We didn’t connect on this fundamental view of what was important. I don’t obsess about material things. I’m the kind of person, if I had $100, I’d see a play; I’d have an experience. Her sense of joy came from owning a Gucci bag.”
She decided it was time to let her friend go. So Ms. Brunner took the “bad-boyfriend approach” and just stopped calling. After the friend made a few spurned overtures — and after some awkward conversations about why Ms. Brunner was always too busy to get together — the friend got the hint. Years later, however, the breakup still feels unresolved.
“I wish I would have handled it differently,” Ms. Brunner said. “I think you owe it to that person, rather than keeping them guessing.”
For 1,600 years, this city — Turkey’s largest — has been built and destroyed, erected and erased, as layer upon layer of life has thrived on its seven hills.
Today, Istanbul is a city of 13 million, spread far beyond those hills. And on a long-farmed peninsula jutting into Lake Kucukcekmece, 13 miles west of the city center, archaeologists have made an extraordinary find.
The find is Bathonea, a substantial harbor town dating from the second century B.C. Discovered in 2007 after a drought lowered the lake’s water table, it has been yielding a trove of relics from the fourth to the sixth centuries A.D., a period that parallels Istanbul’s founding and its rise as Constantinople, a seat of power for three successive empires — the Eastern Roman, Byzantine and Ottoman.
While there are some historical records of this early period, precious few physical artifacts exist. The slim offerings in the Istanbul section of the Archaeological Museums here reflect that, paling in comparison with the riches on display from Anatolia, Mesopotamia and Lebanon.
So Bathonea (pronounced bath-oh-NAY-uh) has the potential to become a “library of Constantinople,” says Sengul Aydingun, the archaeologist who made the initial discovery.
After the drought exposed parts of a well-preserved sea wall nearly two and a half miles long, Dr. Aydingun and her team soon saw that the harbor had been equipped with docks, buildings and a jetty, probably dating to the fourth century. Other discoveries rapidly followed. In the last dig season alone, the archaeologists uncovered port walls, elaborate buildings, an enormous cistern, a Byzantine church and stone roads spanning more than 1,000 years of occupation.
