H-1B visa is for people with high education to take specialty occupations. There is no threshold requirement for the sponsor (the company), either for the size, the income or operation history. Theoretically, if the position offered by your professor's company require special skill that can only be obtained through high education (e.g. a position of design engineer), you should be OK. The fact that the company is new and has only 2 employee would not change the nature of your occupation, but might trigger further scutiny from USCIS in that they may require further information to show that this is a valid genuine business. But they can not deny the application just because the company is young and small. Your should file detailed information in your application to show that the company is a real business and need such a person for this position.