1.59k likes | 1.97k Views
Measuring quantum geometry From superconducting qubits to spin chains. Michael Kolodrubetz , Physics Department, Boston University Theory collaborators: Anatoli Polkovnikov (BU), Vladimir Gritsev (Fribourg)
E N D
Measuring quantum geometryFrom superconductingqubits to spin chains Michael Kolodrubetz, Physics Department, Boston University Theory collaborators: AnatoliPolkovnikov (BU), Vladimir Gritsev (Fribourg) Experimental collaborators: Michael Schroer, Will Kindel, KonradLehnert (JILA)
The quantum geometric tensor • Geometric tensor
The quantum geometric tensor • Geometric tensor • Real part = Quantum (Fubini-Study) metric tensor
The quantum geometric tensor • Geometric tensor • Real part = Quantum (Fubini-Study) metric tensor • Imaginary part = Quantum Berry curvature
Outline • Measuring the metric tensor • Transport experiments • Corrections to adiabaticity • Classification of quantum metric geometry • Invariance of geometry • Classification of singularities • Chern number of superconducting qubit • Berry curvature from slow ramps • Topological transition in a qubit
Outline • Measuring the metric tensor • Transport experiments • Corrections to adiabaticity • Classification of quantum metric geometry • Invariance of geometry • Classification of singularities • Chern number of superconducting qubit • Berry curvature from slow ramps • Topological transition in a qubit
Outline • Measuring the metric tensor • Transport experiments • Corrections to adiabaticity • Classification of quantum metric geometry • Invariance of geometry • Classification of singularities • Chern number of superconducting qubit • Berry curvature from slow ramps • Topological transition in a qubit
Outline • Measuring the metric tensor • Transport experiments • Corrections to adiabaticity • Classification of quantum metric geometry • Invariance of geometry • Classification of singularities • Chern number of superconducting qubit • Berry curvature from slow ramps • Topological transition in a qubit
The quantum geometric tensor Metric Tensor Berry curvature
The quantum geometric tensor Metric Tensor Berry curvature
The quantum geometric tensor • Real symmetric tensor Metric Tensor Berry curvature
The quantum geometric tensor • Real symmetric tensor • Same as fidelity susceptibility Metric Tensor Berry curvature
Measuring the metric tensor Generalized force
Measuring the metric tensor Generalized force
Measuring the metric tensor Generalized force
Measuring the metric tensor Generalized force
Measuring the metric tensor Generalized force
Measuring the metric tensor Generalized force
Measuring the metric tensor • For Bloch Hamiltonians, Neupert et al. pointed out relation tocurrent-current noise correlations [arXiv:1303.4643]
Measuring the metric tensor • For Bloch Hamiltonians, Neupert et al. pointed out relation tocurrent-current noise correlations [arXiv:1303.4643] • Generalizable to other parameters/non-interacting systems
Measuring the metric tensor • For Bloch Hamiltonians, Neupert et al. pointed out relation tocurrent-current noise correlations [arXiv:1303.4643] • Generalizable to other parameters/non-interacting systems
Measuring the metric tensor REAL TIME
Measuring the metric tensor REAL TIME IMAG. TIME
Measuring the metric tensor REAL TIME IMAG. TIME
Measuring the metric tensor REAL TIME IMAG. TIME
Measuring the metric tensor • Real time extensions:
Measuring the metric tensor • Real time extensions:
Measuring the metric tensor • Real time extensions:
Measuring the metric tensor • Real time extensions:
Measuring the metric tensor • Real time extensions: (related the Loschmidt echo)
Outline • Measuring the metric tensor • Transport experiments • Corrections to adiabaticity • Classification of quantum metric geometry • Invariance of geometry • Classification of singularities • Chern number of superconducting qubit • Berry curvature from slow ramps • Topological transition in a qubit
Outline • Measuring the metric tensor • Transport experiments • Corrections to adiabaticity • Classification of quantum metric geometry • Invariance of geometry • Classification of singularities • Chern number of superconducting qubit • Berry curvature from slow ramps • Topological transition in a qubit
Outline • Measuring the metric tensor • Transport experiments • Corrections to adiabaticity • Classification of quantum metric geometry • Invariance of geometry • Classification of singularities • Chern number of superconducting qubit • Berry curvature from slow ramps • Topological transition in a qubit
Outline • Measuring the metric tensor • Transport experiments • Corrections to adiabaticity • Classification of quantum metric geometry • Invariance of geometry • Classification of singularities • Chern number of superconducting qubit • Berry curvature from slow ramps • Topological transition in a qubit
Visualizing the metric Transverse field Anisotropy
Visualizing the metric Transverse field Anisotropy
Visualizing the metric Transverse field Anisotropy Global z-rotation
Outline • Measuring the metric tensor • Transport experiments • Corrections to adiabaticity • Classification of quantum metric geometry • Invariance of geometry • Classification of singularities • Chern number of superconducting qubit • Berry curvature from slow ramps • Topological transition in a qubit