Two-copy distillability of one-copy-undistillable negative-partial-transpose states in every dimension
The study investigates whether one-copy-undistillable negative-partial-transpose (NPT) states can become distillable from multiple copies. The research proves that a specific state, Point C, which is one-copy undistillable in every dimension $d ext{ ≥ } 3$, is actually two-copy distillable. This disproves the conjecture that the entire region of one-copy undistillability remains undistillable for many copies.