Prof. Dr. Joachim Ankerhold
Institute Research
Super Conducting Quantum Circuits
These are key components in superconducting quantum devices, enabling ultra-sensitive measurements and large-scale quantum information processing. We investigate their performance under realistic lab conditions, advancing understanding of quantum transport and interactions in tunneling junctions. …More
Quantum Optics of Nano-Conductors
We study how quantum light interacts with matter, particularly in systems where artificial atoms or Josephson junctions drive microwave cavities. This field, known as Josephson photonics, offers new routes to generate non-classical light for quantum technologies. …More
Non-equilibrium Quantum Dynamics
By applying periodic external forces to quantum systems, we explore stationary states with tunable properties. These driven systems help us design unique quantum states relevant for sensing, simulation, and quantum control. …More
Quantum Thermo Dynamics
We examine how quantum mechanics governs heat and work at atomic scales, focusing on quantum engines and energy transfer in nano-devices. Our research informs both foundational physics and practical device development. …More
Open Quantum Systems
Real-world quantum systems interact with their environments. We develop advanced methods to model these open systems beyond traditional approximations, aiding the control of quantum bits and understanding of dissipative phase transitions. …More
Econophysics
The discipline of econophysics loosely defines itself through the transfer of methods and insights of statistical physics to economic questions. The corresponding analysis of patterns and correlations in financial and economic data allows previous simplifying assumptions to be dropped, resulting in in conclusions on models of causation, and, ultimately, recommendations to market participants and policymakers.
Levitated Particle Arrays
Multiple nanoparticles are optically levitated together to explore light-mediated, non-reciprocal interactions. This work tackles fundamental questions (e.g., when Newton’s third law may seem violated) and paves the way for ultra-sensitive force and torque sensing.
Quantum Nanorotors
By trapping and manipulating asymmetrically shaped nanoparticles, the group harnesses quantum interference effects arising from rigid-body rotations—behavior that has no classical counterpart. These systems serve both fundamental tests of quantum mechanics and next-generation sensors.
Levitated Spin Rotors
Embedding paramagnetic defects in levitated particles produces strong spin–rotation coupling via the Einstein–de Haas and Barnett effects. This interaction allows for coherent control and readout of the particle’s rotational state, unlocking quantum interference with internal spins.
Macroscopic Decoherence
Understanding how large, mesoscopic objects lose quantum coherence when exposed to environmental effects is essential. The team develops theoretical models to quantify decoherence in nanostructures, guiding the design of future quantum experiments.
Molecular Interference
The group uses diffraction of large molecules through gratings to probe molecular properties—such as polarizability and absorption—and to manipulate their quantum states. This merges precision measurement with control over molecular quantum behavior.
Topological Data Analysis (TDA)
Topological Data Analysis (TDA for short) uses topology to reveal structure in complex datasets by analyzing features like loops and voids, offering robust, noise-resistant insights. Our group reformulates TDA as a fermionic many-body problem, mapping data structures to fermionic Hilbert spaces. This enables the use of quantum many-body tools for novel data analysis approaches.
Lattice Gauge Theory (LGT)
Lattice Gauge Theories discretize spacetime to study gauge theories like quantum chromodynamics, preserving local gauge symmetry and enabling simulations. The Hamiltonian approach focuses on quantum states, ideal for quantum simulation. We use Gauged Gaussian Projected Entangled Pair States, a special tensor network construction, with variational Monte Carlo methods to efficiently find ground states of these theories using tensor network techniques.
Quantum Networks
Quantum networks enable quantum communication, distributed computing, and secure data transfer by linking distant nodes using entanglement. A key challenge is distributing entanglement over long distances, requiring quantum repeaters unlike classical amplifiers. We view the network as a quantum many-body system which allows the use of statistical mechanics and machine learning to optimize its structure and performance.
Nonlocality Detection
Bell nonlocality reveals that quantum correlations can't be explained by local hidden variable theories. Traditionally tested via Bell inequalities, it's hard to extend to many-body systems. In our group, we use energy minimization as an alternative: a Bell operator's ground-state energy signals nonlocality if it drops below a classical bound. This connects quantum nonlocality with many-body physics and optimization techniques like tensor networks.
