If they are legitimate professors or researchers, a “J” visa looks more appropriate than an H-1B
“Professor, scholar, teacher (exchange visitor)”
WIKI
A J-1 visa is a non-immigrant visa issued by the United States to research scholars, professors and exchange visitors participating in programs that promote cultural exchange, especially to obtain medical or business training within the U.S. All applicants must meet eligibility criteria, English language requirements, and be sponsored either by a university, private sector or government program. J-1 visa holders must usually return home for two years following visa expiration so they impart cultural knowledge learned in the United States. In 2022, the State Department issued 284,486 J-1 visas, with a visa approval rate of 88.8%. Between 2001 and 2021, there were 6,178,355 J-1 visas issued by the State Department. In 2023, there were 4,209 J-1 visa sponsors. Certain J-1 categories saw increased percentage increase in visas between 2021 and 2022. For example, The J-1 Visa for Summer Work/Travel increased 134% from 39,647 to 92,619. J-1 Teachers increased 467% from 719 to 4,076. Interns increased 212% from 5,402 to 16,833.
J-1 category
Length of stay
Sponsors
2022 numbers
Student, secondary school One to two academic semesters 70 18,921
College student Duration of study 816 36,532
Research scholar Three weeks to five years 868 24,331
Short-term scholar Six months 847 12,452
Summer Work/Travel Four months 37 92,619
more at:
https://en.wikipedia.org/wiki/J-1_visa