De broglie wavelength and quantum effect

[ChemSiddiqui]

I was wondering if it is possible to tell if an object's physical property will exhibit a quantum effect? Can we make some sort of measurement to check?

 

Taken from Wikipedia (http://en.wikipedia.org/wiki/Matter_wave);

 

his hypothesis would hold true for both electrons and for everyday objects. In de Broglie's equation an electron's wavelength will be a function of Planck's constant (6.626×10−34 joule-seconds) divided by the object's momentum (nonrelativistically, its mass multiplied by its velocity). When this momentum is very large (relative to Planck's constant), then an object's wavelength is very small. This is the case with every-day objects, such as a person. Given the enormous momentum of a person compared with the very tiny Planck constant, the wavelength of a person would be so small (on the order of 10−35 meter or smaller) as to be undetectable by any current measurement tools. On the other hand, many small particles (such as typical electrons in everyday materials) have a very low momentum compared to macroscopic objects. In this case, the de Broglie wavelength may be large enough that the particle's wave-like nature gives observable effects.

 

 

So could we say that measuring the de broglie wavelength can tell us if the objects physical property will exhibit a quantum effect?

 

thanks in advance for any additional help.

[proton]

I was wondering if it is possible to tell if an object's physical property will exhibit a quantum effect? Can we make some sort of measurement to check?

 

Taken from Wikipedia (http://en.wikipedia.org/wiki/Matter_wave);

 

his hypothesis would hold true for both electrons and for everyday objects. In de Broglie's equation an electron's wavelength will be a function of Planck's constant (6.626×10−34 joule-seconds) divided by the object's momentum (nonrelativistically, its mass multiplied by its velocity). When this momentum is very large (relative to Planck's constant), then an object's wavelength is very small. This is the case with every-day objects, such as a person. Given the enormous momentum of a person compared with the very tiny Planck constant, the wavelength of a person would be so small (on the order of 10−35 meter or smaller) as to be undetectable by any current measurement tools. On the other hand, many small particles (such as typical electrons in everyday materials) have a very low momentum compared to macroscopic objects. In this case, the de Broglie wavelength may be large enough that the particle's wave-like nature gives observable effects.

 

 

So could we say that measuring the de broglie wavelength can tell us if the objects physical property will exhibit a quantum effect?

 

thanks in advance for any additional help.

 

I'm not quite sure what you mean by "exhibit a quantum effect" but I can tell you that the wavefunction is related to position measurements of a point particle. However macroscopic objects can't be considered to be point objects. So if the uncertainty in position is larger than the dimensions of the body I'd say that the the de Broglie hypothesis won't apply.

[swansont]

So could we say that measuring the de broglie wavelength can tell us if the objects physical property will exhibit a quantum effect?

 

Having just gotten back from the DAMOP meeting, I'd have to say the answer to this is no, not always. I'm at a loss to give a general explanation, though (this is the impression I get after some discussions and seeing some talks that have turned my brain into tapioca). There are conditions where you can have macroscopic objects with small deBroglie waves displaying quantum behavior. Simply "going large" with the momentum is insufficient.

 

Generally speaking, though, it's a good first cut at making that division.