The subject is the vampire film, but nobody mentions Twilight. There simply isn't enough air in the room to accommodate both that gilt-edged franchise and Jim Jarmusch, whose own vampire film, Only Lovers Left Alive, is elegant, adult and made for a fraction of the cost of a Pattinson blockbuster. Not that we get to talk about that film very much either, because Jarmusch is firm in his determination not to analyse his work or his own artistic stirrings; he would rather dwell on the great 1922 silent film Nosferatu.

Of all vampire films, he says, that was ''the most beautiful, as we all know'', although he is also interested in Danish director Carl Dreyer's ''very odd and unusual'' 1932 film Vampyr, and a Mexican vampire film in the '50s that was the first to feature fangs. These films may not be for everybody, he cautions. ''But, you know, neither are some of the most beautiful things in the history of human expression.''

In the '80s, Jarmusch redefined what American independent film could be with his low-budget, meandering narratives Stranger Than Paradise and Down by Law. Now, at 61, he is still resolutely pursuing his singular hipster vision. Only Lovers Left Alive stars Tilda Swinton and Tom Hiddleston as vampire couple Adam and Eve, and Mia Wasikowska as Eve's trampy little blood-sucking sister. It has been in the works for seven years, the time it took Jarmusch to find sympathetic backers.

A vampire romance seems an unlikely choice of subject for Jarmusch, but he says he has always liked the genre. ''Vampires are outsiders, they're strange, there is a whole history of how they've been developed. Are they monsters? Are they evil characters? I haven't read the Anne Rice books, but I know she started this whole idea of vampires as complex. It is a very poetic thing that starts with English literature, the Romantic poets who were also, of course, outsiders.''

In the great tradition of the genre, Jarmusch adds his own tweaks. None of the ostensible drawbacks faced by those who do not die – the loneliness of centuries after one's flesh-and-blood contemporaries die; the endless company of a closed coterie of blood-suckers; the sheer boredom of a life that never ends – trouble Adam and Eve. On the contrary, they are undead examples of the fact that no matter how long you live, there will never be enough time to read everything or know everything.

Eve travels to Tangiers with trunks of books, unable to leave behind her accumulated thousands of favourites. Adam finds solitary succour in the collapsed industrial landscape of Detroit. A devoted couple, they drift across the world for happy trysts. Despite their exquisite languor, they are fired with excitement when discussing any of Jarmusch's own wide range of enthusiasms: quantum physics, the life cycle of the mushroom, philosophy, guitars, Detroit hip-hop.

For Jarmusch, who is proud to call himself a dilettante, it was simply self-evident that anyone living for centuries must be thrilled by the world. ''It would be awfully boring if they just lived for hundreds of years and didn't know shit about anything; then they would be zombies,'' he says.

''The zombie way is not to see the beautiful, strange, odd things in the world. No matter how long you live as a human, you can never absorb all these amazing things – paintings, designs of bridges, things people think of, scientific inventions! I just wake up thinking: 'Wow, the Higgs boson, they're going to use the particle accelerator, what's going on?' So many things are exciting.''

Only their terrible thirst nags at the vampires – and on this, of course, hangs their tale. ''Vampires are always vulnerable because they have to sustain themselves on blood,'' observes Jarmusch. If they kill people, they live in fear of being tracked down by the authorities or vigilante vampire-killers; according to recent genre convention, a mere shaft of sunlight can burn a vampire to death. ''And then when I was writing this, I was thinking of a vampire now and the difficulty of getting good blood. You can't just chomp down on anybody; it's like bad street drugs,'' he says. Jarmusch's vampires, for all their intellectual vividness, are thin, pale, languid and enervated from lack of nourishment. ''They are not immortal,'' he says. ''They are very fragile.''

Someone suggests Jarmusch, like his vampires, is a young mind in an ageing body. After a moment's bemused reflection on whether this is complimentary or not, he brushes the concept aside. Since he finished Only Lovers Left Alive he has been shooting a documentary about the Stooges that Iggy Pop made him promise to make ''before we both died''.

''Iggy Pop, right, he's, like, 66. He is so excited every time I talk to him about some new thing he's discovered, like some obscure jazz recording or some book about the Egyptians. He probably will be on his deathbed saying, 'Oh man, I read this book, you've got to read it!' I don't know what young or old even means any more. To me it's more about this openness to wonder, to have wonder at being alive. And a lot of it is not pleasant, what we see in our lives, but I think to be open to these things is the key.''

He tries to be open to anything when he is making a film, too. Not that he is an experimental filmmaker – ''I think my films are narratives, it's just a lot of critics wouldn't agree'' – but those stories are simply structured, usually around journeys, giving him room to show incidents and oddities. He doesn't do storyboards or shot lists; he discusses the look and colour of the film at length with his director of photography beforehand, but what is shot is decided day to day. Overthinking anything will wreck it.

Tilda Swinton compared the crew to a jazz band. ''Music and film are the two forms most closely related,'' nods Jarmusch. ''Both pass by you in their own rhythm.''

In an increasingly homogenised cultural world, however, he is uncertain whether he will keep making films. ''My friend Bela Tarr'' – the Hungarian director of uncompromisingly slow cinema – ''is retiring and I respect him so much. Everything is different now,'' he says.

He credits Swinton's encouragement with pushing him forward to make Only Lovers Left Alive. ''She wouldn't let go and so I thought, 'I'm going to do it, no matter what', but it was not a really good way to make films. I will not stop expressing myself – that's sort of my job – but maybe it will be smaller films and music and writing.

''I love cinema," he reassures. "I want to keep making films. But the world doesn't want me to on this level any more. It's not happy to help me. So I don't know.''

Only Lovers Left Alive opens on Thursday.