A couple of fundamental quantum materials can be possible someday.

"Theoretical physicists and experimentalists worked together to measure the mass of a rare isotope expected to form a rare proton halo, publishing the first results from Facility for Rare Isotope Beams (FRIB)’s Precision Measurement Program. Credit: FRIB" (ScitechDaily, Inside the Proton Halo: Precision Measurements Unravel Nuclear Puzzles)

The proton halo is a situation the proton jumps off the atom's core and starts to orbit it. So, why a similar situation cannot happen with neutrons? That means. It is possible that somewhere in the universe can be material where protons and neutrons orbit electron balls. 

The quasiparticle called exciton causes a situation where an electron orbits the hole. The electron-hole is the thing that can act as the glue that can connect electrons. Into an electron ball. In that case, it's possible. That the protons and neutrons can start to orbit that electron ball. 

In normal material electrons orbit the atom core. The protons and neutrons are forming the atom's core. The proton is positive and the electron is negative particle. The electron orbits protons and atoms's nuclei because it's far smaller and lighter than a proton. 

But there is the possibility that an electron starts to orbit another electron. In that case, the other electron has a stronger electric load than the other. The electron-hole is a situation in which one electron leaves its place. Or the electron loses part of its electricity. The other situation is that another electron gets a stronger electricity or energy level than another. There is the possibility that the electron starts to orbit the hole, forming a quasiparticle called an exciton. 

Those holes can act as the glue that puts the electrons together. And that thing can form a situation. That we can call an electron ball. This means that the electron stars could be possible. But if the electron balls are possible that thing makes it possible. That somewhere is forming a quantum material, where protons and electrons orbit the electron balls. 

The proton halo gave the idea of that theoretical but fundamental material. The negative material is the model, where the proton halo locks an electron ball inside protons that can orbit that electron nucleus. If protons start to orbit electrons, that thing can make the atoms interesting, and in some models, the protons and neutrons switch their positions between electrons. 

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Electron carpet. And invisible material. 

The model of beta decay. 

"The radioactive beta decay is due to the weak interaction, which transforms a neutron into a proton, an electron, and an electron antineutrino." (Wikipedia, Weak interaction)

But if those protons and neutrons are without connection. That means they don't form an atom nucleus. In that case, there should not be beta decay and electrons. The photons form in beta decay when an electron loses its energy. And the electron antineutrino interacts with the electron neutrino. 

There is a model in which the electrons anchor over the layer with a proton layer. That electron carper offers the layer that the protons and neutrons can start to orbit that layer. This thing can cause the situation. The W and Z bosons close the photons inside the protons and neutrons.

The interaction between protons and neutrons is the weak interaction. And that should make the material invisible. The thing that makes the material visible is electromagnetism that the transportation or transmitter particle is a photon. The human eye can see photons, but it cannot see W and Z bosons. But that requires that something denies the photon formation or adjusts the photon to a high energy level like to X- or gamma ray level, that we cannot see it. 

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If protons and neutrons start to orbit the electron nucleus. That can make that material invisible to the human eye. The interaction between protons and neutrons is the weak nuclear interaction. And the photons that the over-tuned electrons send make the objects visible. The photon is the electromagnetism's transmitting particle. And that means that the energy, that the electrons get and then release as photons are the things that make the material visible. 

The weak interaction is the W and Z boson interaction. That means that if the atom's shell can turn the electron's interaction into a proton's and neutron's interaction that makes the object invisible. 

https://scitechdaily.com/inside-the-proton-halo-precision-measurements-unravel-nuclear-puzzles/

https://en.wikipedia.org/wiki/Electron_hole

https://en.wikipedia.org/wiki/Exciton

https://en.wikipedia.org/wiki/Standard_Model

https://en.wikipedia.org/wiki/Weak_interaction