Date of birth: 20.07.1947
Place of birth: Frankfurt
Immediately after receiving the degree of B. he became a research fellow in the Research Laboratory of the corporation "International Business meshins" (IBM) in Zurich, Switzerland. Here he began to cooperate with the research of material surfaces. Scientists have approached the problem raised by the fact that before a complete analysis of materials to obtain surface substantially failed. The difficulty lies in the fact that the arrangement of atoms on the solid surface is significantly different from their position within it, so that the known methods of research are useless when it comes to the surface. However, the surface is of great interest, since this is where most of the interaction between the bodies.
In order to study the surface of materials B. and Rohrer decided to use a variant of the quantum mechanical effect known as tunneling. This effect first confirmed experimentally in 1960, at is one of the ways in which is shown a so-called Heisenberg uncertainty principle. According to this principle, named after the German physicist Werner Heisenberg, it is impossible to measure both the position and velocity of an elementary particle. As a result, the position of a particle such as an electron is "smeared" in space: the particle behaves like a fuzzy cloud of matter. This cloud material can "tunnel" or difundirovat between two surfaces even if they are not contiguous, in much the same way as water may seep through the ground from one another in the puddle.
The tunnel effect was well known at the time when B. and Rohrer have started to work together, and has even been used - although sometimes quite rude - the study of the nature of surface interactions in the "sandwich" of materials. All that remained to do B. and Rohrer, so it allow electrons to tunnel through the vacuum, and the idea suddenly proved fruitful. Their approach led eventually to the creation of a new tool called the scanning tunneling microscope. The basic principle underlying this device includes a scanning surface of a solid in vacuo with a thin needle tip. Between the tip and the sample voltage is applied, and the distance between them is maintained so small that electrons can tunnel through it. Emerging as a result of the flow of electrons is called a tunneling current. The magnitude of the tunneling current depends exponentially on the distance between the sample and the tip of the needle. Consequently, the leading tip over the sample and measuring the current, it is possible to map the surface at the atomic scale.
B. and Rohrer for the first time successfully tested tunneling microscope spring of 1981 along with two other employees of the company IBM Christoph Gerber and Edmund Weibel they were able to distinguish the features of a height of only one atom on the surface of calcium-iridium-tin crystals. A similar device was created before and independently of the American physicist Russell Young in the US National Bureau of Standards with the help of some great principle, which provided a much lower resolution.
In the development of the scanning tunneling microscope, a group of IBM met with considerable difficulties: first of all it was necessary to eliminate all sources of vibration noise. The vertical position of the scanning tip dolzhnokontrolirovatsya up to a diameter of an atom fraction, as tunnel current depends strongly on the distance between the tip and the specimen. Street noise and even steps could cause a concussion thin device. First, B. and Rohrer decided to meet the challenge, hanging microscope using permanent magnets over a cup of superconducting lead, set on a heavy stone table. The table itself, they were isolated from laboratory buildings using inflatable rubber tires. To move the needle tip with high accuracy, the piezoelectric materials are used, which are compressed or expanded when it attach to the appropriate voltage. As a result of further improvements in the scanning tunneling microscope can now allow the vertical size of 0.1 angstroms (1 stomilliardnaya of a meter, or about one-tenth the diameter of around a hydrogen atom). Horizontal Resolution of 2 angstrom achieved by using a scanning tip width of only a few atoms wide ends and one atom being developed. Once in the design of the scanning tunneling microscope, improvements have been made, it has become a common tool in many research laboratories. Also vacuum, this tool is effective in many other media, including air, water and the cryogenic liquid. It is used to study different samples, from different inorganic substances, in particular viruses.
B. and Rohrer were divided in 1986, half of the Nobel Prize in Physics "for his invention of the scanning tunneling microscope." The other half received the Ernst Ruska Award zarabotu of an electron microscope. Awarded B. and Rohrer, the representative of the Royal Swedish Academy of Sciences said: "It is obvious that this technique promises very much and we still have witnessed only the beginning of its development. Many research groups in different fields of science are currently scanning tunneling microscope. The study of surfaces is an important part of physics, especially needed in semiconductor physics and microelectronics. The surface chemistry of the reaction also play an important role, for example in catalysis. It is possible, moreover, to fix organic molecules on the surface and to study their structure. this technique Among other applications can be used to study DNA. " Remembering that he felt to learn about rewarding, BA said: "It was wonderful and awful at the same time", as it was a recognition of the great success, but also meant the end of "an exciting discovery".
In 1969 he married Laura B. Vagler, psychologist; they have a daughter and a son.
In addition to research, B. interested in skiing, soccer, tennis, golf and sailing. A talented musician, he composes music, plays the violin and guitar and sings. Since 1986 he is a member of the academic council of IBM, ie It occupies one of the top scientific positions in the corporation.
B. and Rohrer were awarded for their work, in addition to the Nobel Prize, and other awards. In 1984, they shared the prize Hewlett-Packard of the European Physical Society and the International Scientific Prize of the King Faisal and the Saudi government for its efforts to build a scanning tunneling microscope. B. Physical and awarded the prize of the German Physical Society (1982).