Inertial Propulsion: The Potential of Eliminating Electron Mass in Graphene

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SUMMARY

The discussion centers on the implications of eliminating electron mass in graphene, particularly regarding propulsion systems. Participants explore the concept of effective mass, noting that while graphene allows electrons to behave as if they are massless, this does not equate to a physical change in mass. The conversation highlights the distinction between effective mass as a mathematical tool in solid-state physics and its implications for momentum and propulsion, ultimately concluding that the effective mass does not facilitate propulsion due to the conservation of total mass in the system.

PREREQUISITES
  • Understanding of effective mass in solid-state physics
  • Familiarity with the Dirac equation and its application to electron behavior
  • Knowledge of semiconductor physics, particularly in relation to graphene
  • Basic principles of momentum conservation and thermodynamics
NEXT STEPS
  • Research the role of effective mass in solid-state physics and its mathematical implications
  • Explore the properties of graphene and its applications in electronics
  • Study the Dirac equation and its relevance to electron dynamics in materials
  • Investigate the conservation laws in physics, particularly in relation to mass and momentum
USEFUL FOR

Physicists, materials scientists, and engineers interested in advanced semiconductor technologies and the theoretical implications of mass in electron behavior.

  • #31
Mr Vibrating said:
honestly I'm not trying to advocate woo, and wouldn't bother yuz lot if i hadn't been chewing it over a good 6 months already, the fun is finding the flaws yourself after all.. but I'm stumped.

The main problem here is that there is no "easy" answer to your question, the concept of effective mass and how/why is used is very complicated and is not properly covered until you study at the graduate and post-graduate level (and then only if you specialize in an area linked to solid state physics).
It is very possible that most of the material (and in the case of the text you linked to extremely likely) that you've come across has been written by people who don't understand it themselves and many of them might not understand the difference between effective and real mass. Another problem is that graphene is still a "hot" topic and there is a lot of hyperbole, some of it coming from people who should know better.
 
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  • #32
Mr Vibrating said:
Charming exposition lol but are you saying that is the extent of these "independent discoveries" - the mere application of an already-existing curve fitting model? Because the thrust of the issue as far as i could make out were findings that unbound electrons were behaving more like bosons, and that this was the underlying mechanism behind the mobility boost.

Not that the property of effective mass was being adjusted to compensate the effect. Why the papers and big announcements? Why use microscopy when a pen and paper would do..?

To some extent yes. The main reason for why so many people are interested is that graphene is a very interesting material from a technological point of view and it is also a very nice 2D "toy system" which allow us to experimentally study effects that were previously only studied theoretically; but there is very little actuall new physics there (which is why there has been such rapid progress). It is mostly a case of plugging the the dispersion curve of graphene (with the "vanishing" effective mass) into existing models.

(I should perhaphs point out that I belong to a research group where there are several people who work on applcations of graphene, so I am in no way trying to diminish its importance; but it is not THAT interesting from a fundamental point of view)
 
  • #33
ZapperZ said:
But this "mass" in graphene IS the effective mass. I hesitate to tell you to actually read the paper (S. V. Morozov et al., Phys. Rev. Lett. 100, 016602 (2008)), because you seem to have a rather adverse reaction when someone asks you to actually go to the horse's mouth and get the info first hand. One can already reason this out because an 'electron', cannot simply lose its mass for no apparent reason. Thus, when we have a condensed matter system such as this, and one talks about electrons being almost massless, this is a condensed matter physics concept, and we're talking about effective mass. You don't have to accept or believe it if you find it difficult, but that's the fact! You can take it, or leave it. It doesn't matter to me.

Zz.
If you can't provide a free PDF or summit i ain't paying to read, saw the abstract tho and while it may well deal in CMP terms it's not addressing the specific issue. If you've got a subscription Miller et al's Observing the quantization of zero mass carriers in graphene is the physorg source.
 
  • #34
Mr Vibrating said:
If you can't provide a free PDF or summit i ain't paying to read, saw the abstract tho and while it may well deal in CMP terms it's not addressing the specific issue. If you've got a subscription Miller et al's Observing the quantization of zero mass carriers in graphene is the physorg source.

You missed the whole point of my post and the reference. You were asking why all these "effective mass" coming up. I'm showing WHY. Obviously, you didn't get it. Instead, you complained that you have no access to the paper.

Zz.