Prospects for Studies of the Free Fall and Gravitational Quantum States of Antimatter

Table 1

The lifetime of the first gravitationally bound state of antihydrogen above various surfaces.

Surface (porosity)	Lifetime (s)
Perfect conductor	0.11
Bulk silicon	0.14
Bulk silica	0.22
Nanodiamond powder (95%)	0.89
Porous silicon (95%)	0.94
Silica aerogel (98%)	4.6