PRINCETON, N.J. — Iran’s imprisonment of Xiyue Wang, a naturalized United States citizen from China who is a Ph.D. candidate in history at Princeton University, has left his family, colleagues and supporters despondent and outraged. Mr. Wang, 37, was arrested in August 2016 while doing dissertation research at public archives in Iran. The Iranian judiciary said this July that he had been sentenced to a 10-year term for espionage.

His wife, Hua Qu, who lives in Princeton with their 4-year-old son, spoke to The New York Times in an interview this past weekend at the university, where a vigil for Mr. Wang was held to assert his innocence and demand that Iran free him. Here are excerpts:

How did you learn that your husband had been arrested?

From his lawyer. After his disappearance, Princeton engaged a local Iranian lawyer for his case. So he tracked his whereabouts with the Iranian authorities and then he confirmed that he had been detained.

He was still in his apartment. The only difference was he had no passport and laptop. So he was waiting for the call from the police so his passport could be returned. He still had his cellphone, so we had some calls and video chats every day. During those three weeks, we video chatted all the time.

How frequently can you two speak now?

For most of the time in the past year, we spoke on a weekly basis, for 10 minutes every week. In the past year he’s called me on a weekly basis.