We implement small solid-state pure and hybrid QIP systems on common platforms based on fixed or tunable microwave cavities and optical nanophotonic cavities. Various types of solid-state qubits will be connected to these "hubs": Josephson junction circuits, quantum dots and NV centres in diamond. The approach can immediately be extended to connecting different types of solid-state qubits in hybrid devices, opening up new avenues for processing, storage and communication.
The objectives of SOLID are to design, fabricate, characterise, combine, and operate solid-state quantum-coherent registers with 3-8 qubits. Major SOLID challenges involve: Scalability of quantum registers; Implementation and scalability of hybrid devices; Design and implementation of quantum interfaces; Control of quantum states; High-fidelity readout of quantum information; Implementation of algorithms and protocols.
In the theoretical contributions to SOLID we plan to achieve maximal use of the available hardware for universal gate operation, control of multi-qubit entanglement, benchmark algorithms and protocols, implementation of teleportation and elementary error correction, and testing of elementary control via quantum feedback.
An important SOLID goal is also to create opportunities for application-oriented research through the increased reliability, scalability and interconnection of components. The SOLID applied objectives are to develop the solid-state core-technologies: Microwave engineering; Photonics; Materials science; Control of the dynamics of small, entangled quantum systems.
The Toffoli gate is a three-qubit operation that inverts the state of a target qubit conditioned on the state of two control qubits. It enables universal reversible classical computation, forms a universal set of gates in quantum computation together with a Hadamard gate and is also a key element in quantum error correction schemes.
Teleportation of a quantum state may be used for distributing entanglement between distant qubits in quantum communication and for quantum computation. In this publication, the group of Andreas Wallraff at ETH Zurich demonstrated the implementation of a teleportation protocol, up to the single-shot measurement step, with superconducting qubits coupled to a microwave resonator.
We have realized a novel device in which a semiconductor double quantum dot is dipole coupled to a GHz-frequency high-quality transmission line resonator. This approach allows us to characterize the properties of the double dot by measuring both its dispersive and dissipative interaction with the resonator. In addition to providing a new readout mechanism, this architecture has the potential to isolate the dots from the environment and to provide long distance coupling between spatially separated dots.
Tomography is the main method used for measuring the fidelity of an experimentally implemented quantum process. However, it is a very inefficient method since the number of measurements as well as the time needed for the data post-processing scale exponentially with the number of qubits. With the ongoing experimental progress and growth in system size, quantum process tomography will soon become infeasible in state-of-the art experiments.
We have exploited the resonant interaction between three superconducting transmon-type qubits and a microwave transmission line resonator to show that a W-state can be generated with high efficiency in this system by harnessing its collective dynamics. Interestingly, our method also benefits from the √N-nonlinearity of the coupling strength between N qubits and a single field mode.
Transferring the state of an information carrier between two parties is an essential primitive in both classical and quantum communication and information processing. Quantum teleportation describes the concept of transferring an unknown quantum state from a sender to a physically separated receiver without transmitting the physical carrier of information itself.
was a joint research assistant of Prof. Atac Imamoglu and Prof. Andreas Wallraff.Previously he obtained a Master's degree of Electrical Engineering and Information Technology from ETH Zurich.
defended his PhD thesis in October 2013 and continued to work with us until December 2013. Lars is now working as an IT/Engeneering Conslultant at AWK Group in Zurich Oerlikon.
Tobias first joined our group in fall 2007 as a semester thesis student. He then accomplished a master’s thesis at the Nanophysics group of Prof. Klaus Ensslin. After finishing his PhD Thesis in February 2013, which was jointly supervised by Prof. Klaus Ensslin and Prof. Andreas Wallraff, Tobias contiued as a Post Doc until July 2013.
was a PostDoc with us from Sept. 2006 to Aug. 2007. After leaving the Quantum Device Lab Parisa was as a PostDoc in the Quantum Photonics Group of Prof. Atac Imamoglu at ETH Zurich. Parisa holds a PhD in Applied Physics from Harvard University, Cambridge, MA and a B.S. in Physics from Imperial College, London, U.K.
