Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Measuring the Adiabatic Non-Hermitian Berry Phase in Feedback-Coupled
  Oscillators   The geometrical Berry phase is key to understanding the behaviour of quantum
states under cyclic adiabatic evolution. When generalised to non-Hermitian
systems with gain and loss, the Berry phase can become complex, and should
modify not only the phase but also the amplitude of the state. Here, we perform
the first experimental measurements of the adiabatic non-Hermitian Berry phase,
exploring a minimal two-site $\mathcal{PT}$-symmetric Hamiltonian that is
inspired by the Hatano-Nelson model. We realise this non-Hermitian model
experimentally by mapping its dynamics to that of a pair of classical
oscillators coupled by real-time measurement-based feedback. As we verify
experimentally, the adiabatic non-Hermitian Berry phase is a purely geometrical
effect that leads to significant amplification and damping of the amplitude
also for non-cyclical paths within the parameter space even when all
eigenenergies are real. We further observe a non-Hermitian analog of the
Aharonov--Bohm solenoid effect, observing amplification and attenuation when
encircling a region of broken $\mathcal{PT}$ symmetry that serves as a source
of imaginary flux. This experiment demonstrates the importance of geometrical
effects that are unique to non-Hermitian systems and paves the way towards the
further studies of non-Hermitian and topological physics in synthetic
metamaterials.

30
The categories of this paper are: q-alg
2
The categories of this paper are: math
28
The categories of this paper are: alg-geom
6
The categories of this paper are: astro-ph
14
The categories of this paper are: math-ph
24
The categories of this paper are: dg-ga
0
The categories of this paper are: hep-ph
33
The categories of this paper are: plasm-ph
8
The categories of this paper are: hep-ex
7
The categories of this paper are: hep-th
34
The categories of this paper are: chem-ph
10
The categories of this paper are: q-bio
29
The categories of this paper are: funct-an
11
The categories of this paper are: hep-lat
36
The categories of this paper are: cmp-lg
31
The categories of this paper are: ao-sci