中国科学技术大学：量子力学诠释与测量问题（PPT讲稿）Interpretation of Quantum Mechanics - A review

量子力学诠释与测量问题 王文阁 近代物理系,USTC

量子力学诠释与测量问题 王文阁 近代物理系, USTC

Outline 几点历史评论 量子力学形式体系 ●Ⅲ纠缠及几个悖论 ●Ⅵ.测量问题 ●V.关于量子力学诠释的几个学派

Outline ⚫ I. 几点历史评论 ⚫ II. 量子力学形式体系 ⚫ III. 纠缠及几个悖论 ⚫ VI. 测量问题 ⚫ V. 关于量子力学诠释的几个学派

References o M. Schlosshauer, Rev. mod phys. 76, 1267 (2005) o W.H. Zurek, Rev. Mod. Phys. 75, 715 (2003) A Bassi and G.C. Ghirardi, Phys. Rep. 379, 257(2003) o FLaloe, Am J Phys. 69, 655(2001) R.Omnes, Rev. Mod. Phys. 64, 339(1992)

References: ⚫ M.Schlosshauer, Rev. Mod. Phys. 76, 1267 (2005). ⚫ W.H. Zurek, Rev. Mod. Phys. 75, 715 (2003). ⚫ A. Bassi and G.C. Ghirardi, Phys. Rep. 379, 257 (2003). ⚫ F.Laloë, Am. J. Phys. 69, 655 (2001). ⚫ R. Omnès, Rev. Mod. Phys. 64, 339 (1992)

Some historical remarks o About 30 years ago, probably as a result of the famous discussions between bohr einstein Schrodinger, Heisenberg, Pauli, de broglie, and others, the majority of physicists thought that the so-called Copenhagen interpretation"is the only sensible attitude for good scientist o nowadays the attitude of physicists is much more moderate for several reasons:(1) More consist interpretations have been found.(2) The discoveries and ideas of Bell. (3 Advances in experimental techniques makes it possible for fine control of quantum systems

I. Some historical remarks ⚫ About 30 years ago, probably as a result of the famous discussions between Bohr, Einstein, Schrödinger, Heisenberg, Pauli, de Broglie, and others, the majority of physicists thought that the so-called “Copenhagen interpretation” is the only sensible attitude for good scientist. ⚫ Nowadays, the attitude of physicists is much more moderate for several reasons: (1) More consist interpretations have been found. (2) The discoveries and ideas of Bell. (3) Advances in experimental techniques makes it possible for fine control of quantum systems

History of fundamental quantum concepts-three periods. Period 1 o Planck- finite grains of energy in emitting and absorbing radiation, and the constant h bearing his name o Einstein-notion of quantum of light (photon as named much later) o Bohr-quantized, permitted orbits and quantum jumps for atoms

History of fundamental quantum concepts – three periods. Period 1. ⚫ Planck – finite grains of energy in emitting and absorbing radiation, and the constant h bearing his name. ⚫ Einstein – notion of quantum of light (photon as named much later). ⚫ Bohr – quantized, permitted orbits and quantum jumps for atoms

Max Planck Planck,MaX(1858-1947) German physicist who formulated an equation describing the blackbody spectrum in 1900 Wien and Rayleigh had also developed equations, but Wien' s only worked at high frequencies, and Rayleigh's only worked at low frequencies. Planck's spectrum was obtained by postulating that energy was directly proportional to frequency(E=hy) Planck believed that this quantization applied only to the absorption and emission of energy by matter not to electromagnetic waves themselves However, it turned out to be much more general than he could have imagined

Max Planck Planck, Max (1858-1947) German physicist who formulated an equation describing the blackbody spectrum in 1900. Wien and Rayleigh had also developed equations, but Wien's only worked at high frequencies, and Rayleigh's only worked at low frequencies. Planck's spectrum was obtained by postulating that energy was directly proportional to frequency (E=hν). Planck believed that this quantization applied only to the absorption and emission of energy by matter, not to electromagnetic waves themselves. However, it turned out to be much more general than he could have imagined

Albert Einstein March 1905 Einstein sent to the annalen der physik a paper with a new understanding of the structure of light. he argued that light can act as though it consists of discrete independent particles of energy, in some ways like the particles of a gas. His revolutionary proposal seemed to contradict the universally accepted theory that light consists of smoothly oscillating electromagnetic waves. But Einstein showed that light quanta, as he called the particles of energy, could help to explain phenomena being studied by experimental physicists

Albert Einstein March 1905 Einstein sent to the Annalen der Physik a paper with a new understanding of the structure of light. He argued that light can act as though it consists of discrete, independent particles of energy, in some ways like the particles of a gas. His revolutionary proposal seemed to contradict the universally accepted theory that light consists of smoothly oscillating electromagnetic waves. But Einstein showed that light quanta, as he called the particles of energy, could help to explain phenomena being studied by experimental physicists

Niels bohr In 1913 Bohr published a theory about the structure of the atom, by combining Planck's idea of quantized energy and rutherford's model of atom. Bohr proposed that electrons travel only in certain stationary orbits. He suggested that the outer orbits could hold more electrons than the inner ones and that these outer orbits determine the atom' s chemical properties. Bohr also described the way atoms emit radiation by suggesting that when an electron jumps from an outer orbit to an inner one, it emits light Niels bohr 1885-1962

Niels Bohr Niels Bohr 1885 - 1962 In 1913 Bohr published a theory about the structure of the atom, by combining Planck’s idea of quantized energy and Rutherford's model of atom. Bohr proposed that electrons travel only in certain stationary orbits. He suggested that the outer orbits could hold more electrons than the inner ones, and that these outer orbits determine the atom's chemical properties. Bohr also described the way atoms emit radiation by suggesting that when an electron jumps from an outer orbit to an inner one, it emits light

Period 2-wave mechanics Heisenberg -matrix mechanics o De Broglie-associating a wave with every material particle Schrodinger -equation of wave o Born-statistical interpretation of wavefunction o Mathematical equivalence of Schrodingers wave mechanics and Heisenbergs matrix mechanics, and Diracs formal expression

Period 2 – wave mechanics ⚫ Heisenberg – matrix mechanics. ⚫ De Broglie – associating a wave with every material particle. ⚫ Schrödinger – equation of wave. ⚫ Born – statistical interpretation of wavefunction. ⚫ Mathematical equivalence of Schrödinger’s wave mechanics and Heisenberg’s matrix mechanics, and Dirac’s formal expression

Werner Karl Heisenberg Werner Karl Heisenberg December 5,1901- February1,1976) He invented matrix mechanics the first formalization of quantum mechanics in 1925 His uncertainty principle, discovered in 1927, states that the simultaneous determination of two paired quantities, for example the position and momentum of a particle, has an unavoidable uncertainty. Together with Bohr he formulated the Copenhagen interpretation of quantum mechanICS

Werner Karl Heisenberg Werner Karl Heisenberg (December 5, 1901 – February 1, 1976) He invented matrix mechanics, the first formalization of quantum mechanics in 1925. His uncertainty principle, discovered in 1927, states that the simultaneous determination of two paired quantities, for example the position and momentum of a particle, has an unavoidable uncertainty. Together with Bohr, he formulated the Copenhagen interpretation of quantum mechanics