Munich Center for Quantum Science and Technology

Composable logical gate error in approximate quantum error correction: reexamining gate implementations in Gottesman-Kitaev-Preskill codes

Quantifying the accuracy of logical gates is paramount in approximate error correction, where perfect implementations are often unachievable with the available set of physical operations. To this end, we introduce a single scalar quantity we call the (composable) logical gate err...

Compiling Quantum Regular Language States

State preparation compilers for quantum computers typically sit at two extremes: general-purpose routines that treat the target as an opaque amplitude vector, and bespoke constructions for a handful of well-known state families. We ask whether a compiler can instead accept simple...

Truncation uncertainties for accurate quantum simulations of lattice gauge theories

The encoding of lattice gauge theories onto quantum computers requires a discretization of the gauge field's Hilbert space on each link, which presents errors with respect to the Kogut–Susskind limit. In the electric basis, Hilbert space fragmentation has recently been shown to l...

2D theoretically twistable material database

The study of twisted two-dimensional (2D) materials, in which twisting layers create moiré superlattices, has created opportunities for investigating topological phases and strongly correlated physics. The broader potential of a seemingly infinite set of twistable 2D materials re...

Ultrafast Laser-Induced Photothermoelectric Currents in Graphene Junctions in the Mid-Infrared

Abstract We investigate the carrier dynamics in graphene junctions under mid-infrared excitation using ultrafast pump–probe photocurrent spectroscopy. We utilize dual split gate devices to demonstrate that the photothermoelectric effect can dominate the photocurrent response of g...

Tuning the Magnetic Properties of Kitaev Materials via the Antiferromagnetic Proximity Effect: Novel Phases and Application to an α -RuCl3/MnPS3 Bilayer

Abstract In recent years, the increasing level of control over van der Waals (vdW) heterostructures has opened new routes to tune the properties of quantum materials. Motivated by these developments, we examine the potential consequences of interfacing a Kitaev honeycomb magnet,...

Insights Into the Nature of Quantum Emitters in Electron‐Irradiated Hexagonal Boron Nitride

ABSTRACT Quantum emitters in hexagonal boron nitride (hBN) have emerged as a promising solid‐state platform for quantum technology applications. However, a persistent challenge in the field is the unclear origin of many observed emission lines, particularly in the visible range,...

Selective filtering of multi-photon events from a single-photon emitter

Abstract Single-photon purity is one of the most important key metrics of many quantum states of light. For applications in photonic quantum technologies, e.g. quantum communication and linear optical quantum computing, a minimization of the multi-photon error rate is required be...

Efficient Auxiliary-FieldQuantum Monte Carlo UsingIsometric Tensor Hypercontraction

Abstract Auxiliary Field Quantum Monte Carlo (AFQMC) has emerged as a powerful framework for treating strongly correlated electronic systems, offering a favorable balance between computational cost and accuracy. In this paper, we present a novel AFQMC method that uses the isometr...