What’s happening

A high-efficiency plug-and-play superconducting qubit network (Mollenhauer et al.)

We’ve finally completed our first ‘network’ experiment, and the preprint is online!

Michae, Abdullah, Xi and team have been able to realize a very efficient “plug-and-play” interconnect between separate transmon qubit devices. By plug-and-play we mean that you can unplug and re-plug the cable connection, like in interfaces with modern electronics.

Important features of the work:

  • with the right cables, we can boost the quality of the interconnect
  • by choosing the right drive frequencies, we can realize a fast (~ 100ns) Raman-transition between the transmons
  • together, this brings us to the ~1% inefficiency level, and one could actually start thinking about scaling in this way!

Parametrically controlled chiral interface for superconducting quantum devices (Cao et al)

Our first experimental paper is finally on the arXiv!
Xi and team have realized an on-chip circulator that can be interfaced seamlessly with superconducting qubits.

We have developed a circuit composed of 3 flux-tunable ‘SNAIL’ resonators. By parametrically driving these, we can route microwave photons nonreciprocally.

Take-homes:

  • The first prototype is already very good — the directionality is about 1000x;
  • Knowing the basic parameters of the circuit from calibrations, the entire behavior can be modeled quantitatively.
  • From analyzing parameters and model, we think this can be used as a very high-efficiency directional interface for superconducting qubits, for example to isolate them from noise, or to route quantum states in a network of qubits.

Link to the preprint: http://arxiv.org/abs/2405.15086

Loss resilience of driven-dissipative remote entanglement in chiral waveguide quantum electrodynamics (Irfan et al)

Our first theory paper!

Abdullah et al studied the impact of waveguide loss on driven-dissipative stabilization of remote entanglement in chiral waveguide QED.

This work was done together with the Clerk theory group at U Chicago.


Main take-homes of the study:

  • loss is hard to overcome, but it should be possible;
  • interesting (and maybe useful) things happen when multiple qubits are involved — in particular, there is some ‘baked-in’ loss resilience in the scheme.

Link to the preprint: http://arxiv.org/abs/2404.00142

This paper will appear for publication in Physical Review Research.

Open postdoc position

We have a new opening for a postdoc!

This position is for a project focusing on modular quantum computing with superconducting and hybrid quantum circuits.  These efforts will include experimental investigation of open systems and synthetic nonreciprocity.

We’re looking for a person that has a strong track record in experimental quantum science and a good understanding of quantum information. Experience with superconducting circuits and quantum optics formalism are of course a big plus.

We will be collaborating with IBM through the newly established Illinois-IBM Discovery Accelerator Institute (https://discoveryacceleratorinstitute.grainger.illinois.edu). The project includes, for instance, the possibility to do part of the research at IBM. In addition, our work provides numerous opportunities for collaboration and scientific exchange with all members of IQUIST (Illinois Quantum Information Science and Technology Center) and the cross-institute center on Hybrid Quantum Architectures and Networks.

Anyone interested should contact Wolfgang directly.

Fridge install!

The second fridge (‘Demeter’) in our new lab has joined its sibling (‘Niflheim’). Some wiring missing, but hopefully it’ll spit out interesting science soon 🙂

Setting up the bottom loader that we’ll use with the vector magnet.

Zhou et al: Realizing all-to-all couplings among detachable quantum modules using a microwave quantum state router

Our friends and collaborators at Hatlab (with Wolfgang as collaborating author) show a modular quantum computing architecture based on quantum routing with controllable 3-wave mixing.

Full citation: C. Zhou et al., Realizing All-to-All Couplings among Detachable Quantum Modules Using a Microwave Quantum State Router, Npj Quantum Inf 9, 54 (2023).
Link to reviewed paper: http://dx.doi.org/10.1038/s41534-023-00723-7
arXiv: https://arxiv.org/abs/2109.06848

Hello world

Not much else to say about it 🙂

Our lab is currently in the setting-up phase (as of February 2021). We are, however, making rapid progress:

Ále posing next to the newly installed Oxford Instruments Triton 500. This setup is located in the shared IQUIST facility where we will work on quantum networks of superconducting qubits.
Soorya (from Jim Eckstein’s lab) and Ále with an MBE system that allows depositing superconducting films to produce quantum circuits on-chip. A collaboration with the Eckstein lab at UIUC.

We are planning to be fully operational by Summer 2021 and are going to run exciting experiments soon. Check out the research page for a brief overview.