Rice, 24, has joined from West Ham in a deal that could rise to £105m.
He is their third signing after forward Kai Havertz joined from Chelsea in a £65m deal and defender Jurrien Timber from Ajax for £34m.
Arsenal were second last season behind Manchester City, despite leading for most of the Premier League campaign.
“I see him like a lighthouse,” Arteta said of England international Rice. “He is willing to put the light in others, improve others and make the team better.
“We discussed a while ago how he could evolve the team and compliment the players and take that winning hunger into a team with players who really want to push themselves to a different level.
“He has an aura. The experience he has in this league is going to bring the team to a different dimension. He has the physical qualities we were missing for a while.
“The way he talks and presents himself. The ambition he has and his passion for the game is exactly what we needed.”
Rice was restricted to bike work in the first part of training in Washington before Arsenal’s opening pre-season game against Wayne Rooney’s MLS All-Stars today.
Arteta now has a full month to work with the team before the opening Premier League game against Nottingham Forest on 12 August.
Now, the pressure is on. Even legendary former Arsenal boss Arsene Wenger recognises it, tipping the Gunners to win the league, while Arteta certainly feels it.
“For sure,” he said. “After what we did last year, a lot of people are going to talk about what is next.
“In the end, it will be about playing better and earning the right to win every match.
“We made some important signings, like other teams are doing, but when you are Arsenal, you have to handle that.”