For almost a decade it has been a well-established fact that quantum mechanics offers enormous speed-up to certain computational problems. The proposed algorithms are based on the use of bits that behave quantum mechanically, so-called qubits. Several systems have been considered as possible candidates for building a quantum computer, however so far only a few qubits have been successfully created and manipulated experimentally. None of these implementations are believed to be scalable to a large number of qubits.
Advances in microtechnology have in recent years made it possible to fabricate and study solid state devices below the micrometer scale. The relevant energy scale of such devices is typically on the order of 1K, and the discrete nature of the energy spectrum is thus well within experimental reach. Since solid state systems are generally highly scalable, it is widely believed that such systems provide the most promising candidates for implementing a quantum computer.
In the Theoretical Nanotechnology group we have recently entered the field of solid state quantum computing. In particular, we are interested in the possibility of coupling, in a coherent and controllable manner, the spin of two electrons localized in two spatially separated quantum dots in a semiconductor heterostructure. In this setup each of the two spins represent a qubit, and the coupling of the two spins corresponds to a 2-qubit gate – one of the fundamental building blocks of a future quantum computer.
To learn more, please contact Christian Flindt or Antti-Pekka Jauho.