I Macroscopic object wave function

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A composite object made of many atoms exhibits a small de Broglie wavelength due to its large mass, yet recent experiments have shown interference patterns for such objects, like the C60 molecule. Theoretical discussions revolve around whether the wavefunction of a macroscopic object can be understood in terms of the wavefunctions of its constituent particles or if it serves merely as a heuristic tool. The quantum function of large objects can be visualized as being "pinned" by individual particles, with the rigidity of this pinning related to particle momentum, leading to a wavelet-like structure. The de Broglie wavelength is considered an approximation for the total wavelet size when it exceeds the distance between particles, and at higher momenta, the object is better described as the sum of its particles' wavefunctions. The Bohr Correspondence Principle suggests that as the number of atoms increases, the behavior approaches classical Newtonian mechanics.
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A composite object made of many atoms has a large mass hence a small de Broglie wavethength...and we know that recent experiments succeeded to obtain interference patterns even for such objects (for instance the C60 molecule). Did theoretician understood how a wavefunction with such a small wavelength could arise from the wave functions of the smaller particles inside the macroscopic objects that have larger wavethengthes ? Or is the wavefunction of the big object just a kind of heuristic tool that no one should try to understand in term of the subparts wavefuntions ?
 
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De Broglie wavethength is very approximate tool.
The quantum function of large (heavy) object can be visualized as "pinned" (i.e. constrained) by each particle, with each pinning "rigidity" proportional to particle impulse, producing something resembling wavelet. De Broglie wavethength is approximation for the total wavelet size when it is much larger than distance between individual particles. At higher impulses, large object is better described as just sum of wavefunctions of constituent particles.
 
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The Bohr Correspondence Principle says that large number of atoms approaches Newtonian Mechanics.
 
trurle said:
De Broglie wavethength is very approximate tool.
The quantum function of large (heavy) object can be visualized as "pinned" (i.e. constrained) by each particle, with each pinning "rigidity" proportional to particle impulse, producing something resembling wavelet. De Broglie wavethength is approximation for the total wavelet size when it is much larger than distance between individual particles. At higher impulses, large object is better described as just sum of wavefunctions of constituent particles.
Thanks ! very interesting, Would you have a reference on the subject ?
 
Is there proof of the correctness of the de Broglie wavelength for macroscopic objects?
The proof based on the analogy with light for elementary particles is familiar to me.
 
fhenryco said:
Did theoretician understood how a wavefunction with such a small wavelength could arise from the wave functions of the smaller particles inside the macroscopic objects that have larger wavethengthes ?
See my paper https://arxiv.org/abs/1406.3221 Sec. 2. The idea is to represent N particle positions by one center-of-mass position and N-1 relative positions. The center of mass has a large mass (the sum of all individual masses), so it has a small wavelength.
 
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For the quantum state ##|l,m\rangle= |2,0\rangle## the z-component of angular momentum is zero and ##|L^2|=6 \hbar^2##. According to uncertainty it is impossible to determine the values of ##L_x, L_y, L_z## simultaneously. However, we know that ##L_x## and ## L_y##, like ##L_z##, get the values ##(-2,-1,0,1,2) \hbar##. In other words, for the state ##|2,0\rangle## we have ##\vec{L}=(L_x, L_y,0)## with ##L_x## and ## L_y## one of the values ##(-2,-1,0,1,2) \hbar##. But none of these...

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