Workgroup on Measurement Induced Phase Transitions (MIPTs)
We are starting a new workgroup on the recently discovered phenomenon of dynamical phase transitions in quantum many-body systems, called the Measurement Induced Phase Transitions (or MIPTs). This workgroup will involve discussing the recent literature surrounding this topic as regular talks delivered by one of the members of the workgroup, and some new ideas to tackle the important issues. This work group will be managed by Sang-Jun Park and Anna Sczapanek.
Introduction to MIPTs
The last two decades have led to an increasingly precise control of quantum systems, mostly driven by the hope of building a quantum computer. Along with this, a lot of research has been dedicated to discovering novel phenomenon that occur in quantum many-body systems which may be experimentally realised on these new technologies. Measurement Induced Phases in Quantum many-body chaotic dynamics has received a lot of attention in the quantum information and condensed matter community in the last 6 years, since its discovery by Li, Chen and Fisher and independently by Skinner, Nahum.
Imagine you have a many-body quantum system, for example, a 1 dimensional chain of qubits (or equivalently for condensed matter theorists, spin-1/2 particles) in some product state \(|\psi \rangle = {| 0 \rangle}^{\otimes n}\). At each time step, system is evolved with the application of local unitaries \(U_{ij}\) that only couple 2 qubits \({i,j}\) at a time. Now at a time \(t\), if we measure the entanglement across a bipartition of this system, let’s assume \(A,A^c\), we will find that the entanglement grows linearly with time \(t\).