This!
I found in university, strangely through sheer accident, (during the first two years of my PhD program in physics) that I performed best on my final exams and written qualifiers with three hours of sleep.
I would sleep 3 hours after late-night study, drink a lot of coffee, and then be able to hyper-focus like a felon on a three-hour-long exam.
How was the recovery?
Not ideal, but in some cases manageable for several days.
Eg, I remember doing 3 qualifiers on Mon, Wed, and Fri in one week, so a small nap and then back to studying for the next one.
Not a fun week, that.
This phenomenon is usually followed by a deep slump in productivity after that dopamine rush wears off.
Oddly enough, for people with ADHD, a poor sleeping schedule might actually help (in the short term) with concentration issues!