JQI

Much like classical computing, quantum computers follow an abstraction model for their architecture. The performance of a quantum computer is dependent on the performance of each layer of this abstraction model, as well as the model itself. Due to its centrality in the quantum computing stack, the control system (consisting of hardware, firmware, and software) plays a strategically outsized role in the problem of quantum architecture.

Abstract: We introduce parallel-sequential (PS) circuits, a family of quantum circuits characterized by a tunable degree of entanglement and maximum correlation length, which interpolates between brickwall and sequential circuits. We provide evidence that on noisy devices, properly chosen PS circuits suppress error proliferation and exhibit superior trainability and evaluation accuracy when employed as variational circuits, thus outperforming brickwall, sequential, and log-depth circuits in [Malz*, Styliaris*, Wei*, Cirac, PRL 2024] across most parameter regimes.

The remarkable precision of optical atomic clocks enables new applications and offers sensitivity to novel and exotic physics. In this talk I will explain the motivation and operating principles of a multiplexed strontium optical lattice clock, which consists of two or more atomic ensembles of trapped, ultra-cold strontium in one vacuum chamber. This miniature clock network enables us to bypass the primary limitations to atomic clock comparisons and achieve new levels of precision. 

Recent experimental progress in realizing and controlling two-dimensional semiconductors has enabled the investigation of a vast class of strongly correlated states of matter, including correlated insulators and fractional quantum anomalous Hall states. Such states have been found in twisted moiré heterostructures of Transition Metal Dichalcogenides (TMD). In this talk, we discuss how excitons—bound states of electrons and holes—in TMD heterostructures can be used as in-situ probes of a periodic charge modulation of correlated insulators [1].

Quantum error correction is usually implemented via an active schedule of discrete error syndrome
measurements and adaptive recovery operations which are hardware intensive and prone to
introducing and propagating errors.  In this talk, we will discuss our recent series of experiments
tailoring continuous dissipative processes in superconducting circuit QED to implement autonomous
error correction for qubits encoded in bosonic cavity states. We will focus on two generations of

The coherent manipulation of macroscopic quantum systems with light is a frontier for controlling materials properties. Ultrafast pump-probe experiments have enabled the selective manipulation of quantum states in materials, while advances in coupling quantum materials to photons in a resonant cavity promise to extend quantum-optical techniques and cavity quantum electrodynamics to correlated electron systems.

We provide an overview of ongoing research in quantum simulation at IQOQI Innsbruck. This includes the development of bounded-error quantum simulation techniques based on Hamiltonian and Liouvillian learning, along with initial experimental implementations using trapped-ion systems. Furthermore, we investigate inverse quantum simulation as a novel approach to quantum material design with quantum simulators.

Peter Zoller - Institute for Theoretical Physics, University of Innsbruck, and IQOQI, Academy of Sciences, Innsbruck, Austria

The nitrogen vacancy (NV) center in diamond exhibits spin-dependent fluorescence and long spin
coherence times under ambient conditions, enabling applications in quantum information processing and
sensing. NV centers near the surface can have strong interactions with external materials and spins, enabling
new forms of nanoscale spectroscopy. However, NV spin coherence degrades within 100 nanometers of the
surface, suggesting that diamond surfaces are plagued with ubiquitous defects. I will describe our recent