# What does the phrase “atom-like system” refer to?

In several papers and contexts I've seen this phrases like this used:

The nitrogen-vacancy in diamond is an atom-like system in the solid state.

What does "atom like system" mean exactly? I've done a google search and turned up little. It seems to be a field specific term. My guess is that the system of (for example) a nitrogen and vacancy pair can be modeled together using standard atomic model (like the standard hydrogen atom system that's studied in QM).

An explanation of what it specifically means, i.e. what assumptions you can make about the system that defines it as "atom like" would be appreciated.

• I know sometimes people describe superconducting circuits as like "artificial atoms." See for example here: nature.com/nature/journal/v474/n7353/full/nature10122.html . Maybe this is the same idea. All it means in that case is that the system is a quantum system with discrete, unevenly spaced energy levels, and I've always found it to be a rather annoying piece of jargon. – Rococo Feb 23 '17 at 22:19
• $\uparrow$ Which papers? – Qmechanic Feb 23 '17 at 22:34
• @Rococo I'm a practicing member of the superconducting qubit field, and I too find that particular piece of jargon to be unhelpful and even counterproductive. I can't tell you how many times I've seen researchers start a talk about superconducting qubits with a cartoon of an atom in a Fabrey-Perot cavity and thought to myself "You're talking to a room of circuit people, so why are you trying to introduce your work with a diagram from AMO?". – DanielSank Feb 23 '17 at 22:44
• @Rococo Mind you, a "quantum system with discrete uneven energy spectrum" is a notion that could do with a good, succinct moniker in some applications and discussions. – Selene Routley Feb 23 '17 at 23:28
• @sammygerbil To be frank, the phrase is common enough that no reference is really needed here. – Emilio Pisanty Feb 27 '17 at 15:35