What's the minimum software requirements to create a AR experience?

For the Vuforia Studio -you need a windows or mac platform with medium performs to be able to install Vuforia studio.

On windows it could be windows 10 with chrome 8- 16 GB Memory and node installation. Also, low performance devices it will work for the studio installation  with enough performance - no problem. So, I think- you can use a machine mac or windows which will works reasonable for some Desktop application like Microsoft office (in the meantime office requires also a lot of system resources)

But depending on the complexity of the models you want to use- a geometry with high complexity and also some shader features  etc. or any  development for HoloLens where you try to use also Vuforia engine with unity and AR toolkit - in this case it will be better to have a laptop / or notebook with better graphical performance

Please, refer to the Studio Help: http://support.ptc.com/help/vuforia/studio/en/#page/Studio_Help_Center%2Fcommon%2FVuforiaBeta_InstallThingBuilderMac_Commercial.html%23