December 11, 2011 12:21
If you do ever tried to do this, you already know that it is impossible to pass through the wall. However subatomic particles can do this because of the effect, which is called quantum tunneling.
Now physicists say that this process can be seen on the man-made objects, although this causes a lot of doubt on the part of other scientists.
If the experiment is successful, it will mean a big jump in the design of mechanical systems that behave as quantum-mechanical objects. In 2010, scientists have taken the first step in this direction by introducing a tiny object in a state of motion, which can only be described by the laws of quantum mechanics. Tunneling on the background of this would look like a big achievement.
So how do you look quantum tunneling? Imagine that an electron is fixed in one of two low-energy states, or points that can be imagined as the energy pits, separated one from another small hill, which is the electric field. To go up the hill and hit the bottom with one point to another, it has to roll up the hill, with enough power. If the energy is small, the classical physics say that it will never reach the top of the hill and will not pass it.
These tiny particles, like electrons, can still cross it, even with a lack of energy to climb the hill. Quantum physics describes such particles as waves of probability, and because it appears that there is a possibility that one of them suddenly "tuneliruet" just over the hill and suddenly will have on the other side to the other low-energy point, even if the electron and can not occupy the upper point between them.
It sounds unbelievable, but scientists and engineers to show the effect of quantum tunneling in superconductors, where electrons tuneliruyut through layers of material that does not conduct Struma. (And even more, some types of magnetic hard disk drives used in their work tunneling effect for reading.) And tunneling microscope, which won the Nobel Prize, the electronic tunneling in the gap between a tiny tip and the sample surface. Up to now no one has observed the pores of such an effect (passing through a certain barrier) at a macroscopic object.
But Mika Sillanpää, together with colleagues from the Aalto University in Finland says that it is possible, just using a tiny device that resembles a trampoline. Thus, the researchers plan to develop a sort of a trampoline millimeter scale of graphene — superkrepkogo and superplasticheskogo thick carbon only one atom.
Then pull it over the metal plate as a membrane — a small, but much larger than atoms and molecules, which are used in quantum physics. When experimenters served voltage membrane must have two stable positions: one in which it is slightly curved in the middle, and one — when it bends enough to touch her below the plate.
The final design assumes that the electrical and mechanical forces on the membrane creates an energy barrier between the two positions. If researchers will reduce the energy of the membrane by cooling to a temperature of thousands of times smaller than for the absolute zero, the only way to move between the two positions just would become the phenomenon of quantum tunneling. Then would the experimenters might observe changes in the membrane capacitance of the system — a figure that shows how much it can store electrical charges. Sillanpää says, to achieve the low temperatures needed for several years.
Quantum tunneling in a mechanical system — is the Holy Grail, which is now looking for people, says physicist Lawrence with Darmutskogo college. But the experiment is not simple. Physicist Gil-Ho Lee said that the proposed experiment is an important step demonstration of quantum tunneling. But he believes that this is not enough, since the membrane should show the same "switch" from one position to the other, with a small absorbing excess energy as heat. He says that researchers quantum tunneling in electrical systems are familiar with the Josephson effect, which also met with similar problems in 1980, while experiments finally confirmed tunneling.
Why are you still can not walk through walls? Calculations of quantum mechanics tells us that the probability of this is so small that even waiting for the end of the world, you can never find a "second self" on the other side of the wall.