# What is Matter waves: Definition and 40 Discussions

Matter waves are a central part of the theory of quantum mechanics, being an example of wave–particle duality. All matter exhibits wave-like behavior. For example, a beam of electrons can be diffracted just like a beam of light or a water wave. In most cases, however, the wavelength is too small to have a practical impact on day-to-day activities.
The concept that matter behaves like a wave was proposed by French physicist Louis de Broglie () in 1924. It is also referred to as the de Broglie hypothesis. Matter waves are referred to as de Broglie waves.
The de Broglie wavelength is the wavelength, λ, associated with a massive particle (i.e., a particle with mass, as opposed to a massless particle) and is related to its momentum, p, through the Planck constant, h:

λ
=

h
p

=

h

m
v

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{\displaystyle \lambda ={\frac {h}{p}}={\frac {h}{mv}}.}
Wave-like behavior of matter was first experimentally demonstrated by George Paget Thomson's thin metal diffraction experiment, and independently in the Davisson–Germer experiment, both using electrons; and it has also been confirmed for other elementary particles, neutral atoms and even molecules.

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1. ### I Relativistic Velocity Addition: Calculating Electron Speed

If we imagine launching an electron wave in a reference frame S with speed v, should someone viewing the electron from frame S1, which is in inertial motion referring to S, use the relativistic velocity addition to calculate the speed of the electron?
2. ### I Could Planck-Einstein relation be applied to matter waves?

My friend gave me some statements which are wrong, but I could not tell why they are wrong. He wrote, Since ##\omega = \frac E \hbar = \frac {\hbar k^2} {2m} = k v##, then##p=\hbar k =2mv##. I guess that ##E =\hbar \omega## may only appied to photons, not matter waves. Is that correct?
3. ### I Finding de Broglie's Original Paper on Matter Waves

I was searching for d Broglie's original Papper of matter waves, I didn't get any thing on internet, please anyone help on this?
4. ### Calculating the frequency of a free electron

I feel like I must be missing something obvious, but I can't figure it out. I have the speed of an electron, and to calculate its frequency i used p = h/λ, then subbed in p =mv and λ= v/f. Giving me the equation f = mv2/h. However, I also could use E = 1/2 mv2 and E = hf to give me the equation...
5. ### I Are fundamental particles like electrons and protons truly matter waves?

Hi at all, I've the following question: How the fondamental particles (electrons, protons) are seen as matter waves, what shape and size should be these waves? They are wave-packets?
6. ### I Energy associated with matter waves of macroscopic objects

Consider an object of mass 1kg moving with a speed of 1m/s. Theoretically , the de broglie wavelength associated with it is about 3.6x10-37. Now if we calculate the energy associated with this wave it comes out to be 3x1011. This is a huge amount of energy which could be very hazardous but it is...
7. ### I What oscillates in matter waves?

like in sound waves pressure varies(oscillates) and in light electric and magnetic field oscillates
8. ### I De Broglie Matter Waves: Where Does the Fraction Come From?

In de Broglie's original proof of the theorem of phase harmony, the frequency of the moving wave of energy mc^2 (not the internal periodic phenomenon wave) is multiplied by the following term ##freq * ( t - \frac{\beta * x}{c} ) ## Does anyone have an idea where the fraction comes from? All...
9. ### Light Waves on Macroscopic Scale: Distinguishing from Matter Waves?

scientists have observed light acting as waves on a macroscopic scale before the quantum characteristics of particles were discovered. My question is what sets apart the macroscopic wavelike characteristcs of light apart from other matter waves? This may be a stupid question but can the...
10. ### Experimental verification of matter waves?

I am told that even macroscopic objects like footballs obey the wave equations of quantum mechanics. Is there any experimentally based reason to believe this, or is it just said as a way of generalizing the theory?
11. ### Dispersion relation for non-relativistic quantum particles

In class I learn that we can get the dispersion relation for particles by using E=hbar*w and p=hbar*k. The calculated phase velocity is w/k = hbar*k/2m, while the group velocity is dw/dk=hbar*k/m. All these make sense to me, except one thing: I always thought that E=hbar*w=hf is only applicable...
12. ### Matter Waves and Electromagnetic Waves

I don't know if this question should be in the quantum physics section, so I'm just posting it here. So I have doubts regarding matter wave and electromagnetic waves associated with electron or just any particle. 1. So I understand when an electron is accelerated, it produces electromagnetic...
13. ### Conceptual help: matter waves and light waves

Ok so I'm coming to terms with the following: 1 - Matter is not a wave, nor does it propagate as a wave. There is no physical wave, amplitude, etc. The probability of the position of matter varies in a wave-like pattern. It is often called a wave because physicists have no explanation for why...
14. ### Doppler effect in matter waves

If I have a matter wave (for example, electron waves in a electronic microscope) at a given wavelength λ, and I move with respect (towards) them at speed v, I will measure a Doppler shift in the wave given by: \frac{1}{{\lambda '}} = \frac{1}{{\lambda '}}\left( {1 + \frac{v}{{v_e }}} \right)...
15. ### DeBroglie matter waves and double-slit

Homework Statement A beam of electrons with a kinetic energy 1.00 MeV strikes normally at an array of atoms separated by 0.25 nm. in what direction can we expect the electrons in the fifth order? Homework Equations Ek= hf - W p=h/λ dsinθ=nλ The Attempt at a Solution i tried my...
16. ### Do the properties of matter waves mirror that of the particle?

Matter (deBroglie) waves is a concept and it's existence is not confirmed (?)..that said, We know that - The de Broglie equations relate the wavelength λ to the momentum p, and frequency f to the total energy E (including its rest energy) of a particle how closely do the properties of matter...
17. ### Wavelength of matter waves at speed equal to zero.

According to de-broglie's equation λ=h/p, so a/c to this equation what would be wavelength of particle at zero speed?
18. ### What causes the existence of matter waves?

My book does not explain this and i can't rly find a simple explanation for this on google and my professor basically dodged my question: So the de Broglie wavelength formula basically says that matter creates waves with wavelength h/p, where p is the matter's momentum. However, when the...
19. ### Matter waves of various particles - do they interact?

this has been asked by someone before, though, but, i think, never got answered can the matter waves of, say, a photon, interact with the matter waves of, say, an electron? matter waves = de Broglie waves lets say we have two pairs of double slits...a photons is sent through one pair...
20. ### What Is a Matter Wave?

Could anybody give me a good definition of what a matter wave is? I am studying electromagnetic waves for my final exam, and unsure of the definition! I looked it up on the net a few times but it wasn't direct at all. Thankyou!:)
21. ### Matter waves - Real or Hypothetical?

Hi my expert friends, I'm confused with these seemingly two contradictory statements: 1- Phonons are the quantized quasi-particles of the normal modes of lattice vibrations and we have Longitudinal (LA) and Transverse Acoustical (TA) Phonons and Longitudinal (LO) and Transverse Optical...
22. ### Exploring the Physical Interpretation of Matter Waves in Quantum Theory

Hi, I am trying to understand whether quantum theory provides any sort of physical interpretation of matter waves. So far, I have been attempting to work my through some of the developments, but possibly failing to grasp what appear to be some fairly fundamental issues. Therefore, I was hoping...
23. ### Exploring the Differences Between Photon and Matter Waves

I know electromagnetic field is not the wave function of photons. Photons have their own wave function like how matter waves like electrons have their own wave functions. But why do photons produce electromagnetic wave while other moving*particles like neutrinos don't? What properties (spin...
24. ### Understanding De Broglie Matter Waves: How to Simplify E/p=c^2/v?

Just a very quick question: in my notes I have the velocity of a DeBroglie wave is given by: \nu\lambda=2\pi\nu\frac{\lambda}{2\pi}=\frac{\omega}{k}=\frac{E}{p}=\frac{c^{2}}{v} I can't figure out how he want from E/p=c^2/v. I think the assumption is made that E is approximately equal...
25. ### Matter Waves: Phase vs Group Velocity Equation

Homework Statement In a particular substance the phase velocity of the waves is proportional to the reciprocal of the wavelength. If vp represents the central phase velocity of a wave group and vg represents the group velocity, which of the following equations is valid? Homework...
26. ### Understanding Matter Waves and the de Broglie Hypothesis in Quantum Physics

According to the de Broglie hypothesis particles like electrons can have a wavelength and be treated as waves for instance when confined in atoms. What I fail to understand is what exactly waves, I mean, in what medium does the electron wave? is it empty space, like photons? Perhaps this is...
27. ### How Do Electron Wavelengths Influence Diffraction Patterns?

Homework Statement An electron is traveling at the "non-relativistic" velocity of 0.05 times the speed of light. Find its de Broglie wavelength. Explain what size an object needs to be in order to cause a stream of such electrons to form a significant diffraction pattern. Homework...
28. ### Matter waves are oscillations in what medium?

Greetings, I have been thinking as everything being particles and only appearing wavelike in double-slit experiments because they were in superposition. Now I am reading that they are really only waves. Waves in what medium? Thanks
29. ### Matter Waves: What Does Frequency Represent?

I asked a question very closely related to this a couple months ago here https://www.physicsforums.com/showthread.php?t=319693 so I'm not sure if this should be a new thread or a continuation of the old one. In any case, one of the premises used in constructing the Schrodinger equation is...
30. ### Electron and matter waves: WE NEED HELP

Electron and matter waves: WE NEED HELP! Homework Statement Calculate the de Broglie wavelength of (a) a 1.00Kev electron, (b) a 1.00Kev photon, and (c) a 1.00KeV neutron Homework Equations K = mv^2 / 2 p = mv p = sqrt 2KM m of electron is 9.11 * 10^-31 kg 1 ev = 1.6 *...
31. ### Photons and matter waves: The photon of quantum light: I

Homework Statement How fast must an electron move to have a Kinetic Energy equal to the photon energy of sodium light at wavelength 590 nm. Homework Equations photon energ E =hf h = 6.63 * 10 ^ -34 J * s = 4.14 = 10^-15 eV *s f = c/ lamda c = 3 * 10^ 8 m/s mass of an...
32. ### Calculating Angle in Two-Slit Experiment with High-Speed Protons

Homework Statement A stream of protons, each with a speed of 0.8250c, are directed into a two-slit experiment where the slit separation is 2.00 10-9 m. A two-slit interference pattern is built up on the viewing screen. What is the angle between the center of the pattern and the second minimum...
33. ### Matter waves as standing waves

Hi all,can anyone tell me the meaning of lines that i had read from a book: "The electron is situated within a distance of 10 to the power -8 to 10 to the power -10 m. from the nucleus and is always confined only within this distace. The matter waves associated with electron is defined in terms...
34. ### Matter Waves As Standing Waves

IN an atom why the matter waves associated with electron is regarded as standing wave having varying amplitude within a region and zero outside the region
35. ### What Does the Wave Function y(r,t) Represent in Quantum Mechanics?

Just get started with quantum so I have a simple question. Does a matter wave describe the probability of the particle to be in a certain place, or is it the wave squared? In other words, is y(r,t) = Probability(finding particle at r and time t) or y(r,t)^2 dV = Probabilty(finding...
36. ### What is the derivation of de Broglie wavelength and its relationship to energy?

At school, I am taught that the "derivation" of de Brogle wavelength of a matter wave is as follows. E=mc^2, E= h\nu So mc^2=h\nu Then setting c=v by analogy derive the exp. for de Broglie wavelength. Here's the problem, I can't understand in what context the two energies are...
37. ### Are matter waves electromagnetic?

Matter waves such as an electron have energy, frequency, wavelength. But are they part of the electromagnetic spectrum? I assume not since they are electrons, protons etc, not photons. Only photons belong in the electromagnetic spectrum? So if not than what are they part of? Thanks
38. ### Matter Waves and the Speed of Light: Exploring Wave-Particle Duality

Why do matter waves (as in wave-particle duality) travel faster than light? How is it possible?
39. ### Could matter and matter waves be derivable?

Is this a load of codswallop, or is there a ring of truth here? http://www.spaceandmotion.com/chris-hawkings-wave-theory.htm
40. ### What is the relationship between wavelength and probability for matter waves?

I was told that for an electron, the wave length lamda calculated from De Broglie's equation ( = h/p ) refers to the wave length of its probability function (as solution to Schroedinger's wave equation ), and is not its physical wave length as exhibited in the electron's double slit diffraction...