Andrés Rosario Hamann visits QUANTIC group

Last week we had the visit of Andrés Rosario Hamann, from the SQD group led by Prof. Arkady Fedorov at the University of Queensland at Brisbane (Australia).

Andrés visited BSC and Mare Nostrum (see pic) and also ICN2, where Dr. Forn-Díaz is setting up the laboratory of Prof. Valenzuela. Andrés presented his work on a quantum diode built out of two superconducting qubits in a waveguide.

Thanks for visiting us Andrés!


Workshop Quantum Simulation and Computation in Bilbao

Last month we witnessed one of the most important events in the Quantum Simulation and Computation scene in the world this year. The workshop in Bilbao contained a set of the leading scientists in the world in all areas of quantum information, particularly experimental quantum computation and simulation.

Besides, a couple round tables made the event even more special. A first round table moderated by Enrique Solano and Gavin Brennen with scientists discussed the future of quantum computation, the challenges and the visions from top players in the field such as Rainer Blatt (Innbruck), Michel Devoret (Yale), Alan Aspuru-Guzik (Harvard), Jens Eisert (Freie Universität Berlin), Christine Muschik (IQC Waterloo), Frank Wilhelm (Universität des Saarland). A second round table with representatives from the corporate world was moderated by Víctor Canivell, president of the Quantum World Association, and included Sergio Boixo (Google), Will Zheng (Rigetti), José Ignacio Latorre (Qilimanjaro), Arman Zaribafiyan (1QBit), Toni Juan (Metempsy).

The QUANTIC team was represented twofold. First, Artur García-Sáez presented preliminary results on a new type of quantum algorithm known as ‘Adiabatically Assisted Variational Quantum Eigensolver’ (AAVQE) which is currently being written up. The second participation was from José Ignacio Latorre who participated at the industrial round table and explained his views from the position of a scientist trying to raise private funds.

The event was co-organized by Enrique Rico (Bilbao), Juan José García-Ripoll (IFF-CSIC, Madrid) and Pol Forn-Díaz (QUANTIC).

New publications by QUANTIC team

Last month was busy, we will be updating the news section with more posts soon.

Some of the most important news relate to publications. The QUANTIC team has added a new preprint of a theory paper on Multipartite entanglement on the publications section titled ‘Multipartite entanglement in spin chains and the Hyperdeterminant‘. The work led by Alba Cervera-Lierta from QUANTIC team studied classes of entangled states and a measure for their ‘entanglement-ness’, called hyperdeterminant. It turns out you need four qutrits to yield maximally entangled states.

In addition, one of the papers under review by Dr. Forn-Díaz has been accepted to the prestigious journal Nature Communications. The work entitled ‘Probing the strongly driven spin-boson model in a superconducting quantum circuit‘ is a combined theory and experiment study of the well-known spin-boson model, taken in a new domain of parameters. Using a superconducting flux qubit coupled to a transmission line, combined with a strong drive on the qubit, led to a dressed state picture in the strongly dissipative regime, which had not been studied yet. The result is important in the area of analog simulation of condensed-matter models using superconducting circuits.

Qubit spectral traces as function of applied strong drive amplitude (y-axis). The splitting is a signature of the strong dissipative regime of the spin-boson model and had never before been observed. An extension of the spin-boson model was needed to match the theoretical predictions. Inset shows the superconducting flux qubit used in this work, the arrows represent the superposition of persistent current states of the qubit.

Will Zeng from Rigetti visits us

We have recently received a distinguished visitor at QUANTIC, Will Zeng who is one of the software leaders in the new startup Rigetti Computing, which aim at building a quantum computer. The company recently opened up their 19-qubit small quantum computer for remote user access through their cloud environment. The researchers at QUANTIC are already testing this new technological wonder.

Will led the development of the software and theory teams at Rigetti Computing, including the Forest quantum programming environment.  He started working with superconducting qubits in Michel Devoret and Andreas Wallraff’s labs before his PhD at Oxford on the mathematical structure of quantum algorithms.

It was nice having you around Will!

Will and Alba posing in front of Mare Nostrum 4 at BSC.

We are on Twitter!

Our group has launched a twitter account, @QUANTIC_BSC

Our twitter profile. It’s a Q, using the loop of a flux qubit.

We will be generating content as news from our group and from the world on quantum computation, simulation and in general quantum technologies unfold.

Follow us if you want to be up to date!

Workshop Bilbao Quantum Computation and Simulation

Last week one of the most important events this year on Quantum Computation and Simulation took place in Bilbao. The workshop gathered some of the experts in the field from all over the world, both in the experimental as well as the theory areas. As a novelty, a round table including representatives of the quantum technology industry was chaired by Víctor Canivell, president of the Quantum World Association. Prof. J. I. Latorre participated in the table as a partner of the consultancy Entanglement Partners.

Our group was represented at the workshop as organizers (Pol Forn-Díaz and José Ignacio Latorre) and as presenters. Artur García-Sáez presented his latest work on a non-trivial and potentially useful new quantum algorithm, the adiabatically-assisted variational quantum eigensolver (AAVQE) that caused some sensation. This work is the first project at QUANTIC seeing the light.

Artur García-Sáez introducing the Quantic group in his talk about quantum eigensolvers.

Two new TFG students!

Sergi Ramos and Sergi Duaigües have joined QUANTIC to work on their TFG (‘treball de final de grau’, or undergraduate thesis). They will both join Prof. J. I. Latorre’s theory team to work on coherent quantum annealing and variational quantum algorithms, respectively. They will stay until the end of the semester. Welcome to QUANTIC!

New PhD student!

The QUANTIC family is growing. A new PhD student, Carlos Bravo Prieto, joined the team to work on quantum algorithms. Carlos will be based at UB under Prof. J. I. Latorre. He will work closely with the experimental team at BSC to design a first generation of algorithms for real quantum computers. Welcome Carlos!

New paper on Two-photon Quantum Rabi model

A new publication has appeared led by Dr. Pol Forn-Díaz on the theoretical implementation of the two-photon quantum Rabi model. A purely genuine, two-photon interaction is a very intriguing effect, and it is very difficult to find a system in nature that exhibits such phenomenon. In this work, which is a collaboration with the group of Prof. Solano at UPV-EHU in Bilbao, the team found a superconducting circuit which is described by a purely two-photon interaction. The work also investigated the very intriguing phenomenon of a spectral collapse, when the two-photon interaction exceeds a certain critical value and the spectrum of the systems becomes unbounded. The work appeared in Physical Review A. The full reference is Phys. Rev. A 97, 013851 (2018).

This circuit, consisting of a dc-SQUID and a flux qubit, implements the two-photon quantum Rabi model.