Tuesday, September 11, 2012
[Research] Heisenberg's uncertainty principle is doubt about the accuracy
Lee Rozema (right) and his colleagues are preparing photon pairs in the troubled state (entangled photons) to study the disturbance of them after measurement Famous uncertainty principle of Werner Heisenberg was established in 1927 as one of the pillars of quantum mechanics and has been used a lot so far. In the most basic form of speech, the principle says that it is impossible to measure any one thing that does not disturb it, for example, measure the position will affect the speed and vice versa with uncertainty is determined specific. Recently, researchers at the University of Toronto (University of Toronto, Canada) has proposed a general method to measure the accuracy and level of disturbance of any physical system. Interestingly their results show that Heisenberg's uncertainty assessment is higher than the measurements they made in the laboratory. In other words, according to the research group, the Heisenberg relation is incorrect. "The world is full of quantum uncertainty, but our study we did not have to add too much uncertainty as we often think of [as calculated by Heisenberg system]," Lee Rozema, who led the research Research says. has now been published in the prestigious journal Physical Review Letter, if this result is correct, its influence on quantum mechanics in general and the actual measurements related to quantum systems in particular will be extremely large. Return innovative method of measuring that group, Lee Rozema said they had to design a device to measure the polarization of a photon (light quantum). What they need to do then is to determine the turbulence measured photon before and after measurements with this device are made. But how to measure the photon before using new equipment that least affect it? To overcome this difficulty, Rozema and colleagues used a technique called "weak measurement" (weak measurement) in which the impact of a measurement device are limited to the influence of the older subjects was not be realized. When the photon is sent to the instrumentation, the researchers "weak measurement" normal particles before measuring again later. Surprisingly, the results of comparing the measurements showed that the disturbance caused by the measurement is less than the value required by the uncertainty relation. "When one is just give us a little information about the disturbance, but by repeating the experiment many times we have been able to get the best picture of the level of disturbance of photons," Rozema said . Schematic presentation of the general method to measure the accuracy and level of disturbance of any system: The system is weak measurement before you send them to normal instrumentation Known, before a number of scientists have put in doubt the validity of the uncertainty principle. In 2003, the Japanese physicist Masanao Ozawa for that Heisenberg principle can not be applied properly in the measurements and he proposed an indirect method of testing this. Following this work, in 2010, two other scientists at Griffith University in, Austin Lund and Howard Wiseman, has shown that weak measurements can be used to determine the characteristics of the measurement system quantum. However, due to measurements of two scientists propose the downside is that requires a small quantum computer, it is not possible at the present time. Based on the research that, Rozema's team used a technique called "cluster state quantum computing" (roughly translated: cluster state quantum computing) to simplify quantum computer requires the permission weak measurements and allow for measurement of weak, very important element in the work of the group, in the laboratory at the present time. Detailed interest you can download the article in the journal Physical Review Letter here (need an account), or on the stock documents Arxiv.org in here to read more about this project. Heisenberg's uncertainty relation is represented by the mathematical formula: In the above formula, σ_x is the standard deviation of the position, σ_p is the standard deviation of the momentum, and h is the reduced Planck constant. According to Wikipedia Source: Phys.org ...
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