14 papers
Heisenberg scaling under collective non-parallel directional noise via geometric state design
Francisco Riberi, Milad Marvian, Lorenza Viola
Spin-squeezed states enable entanglement-enhanced frequency estimation; however, the achievable performance is limited in practice by decoherence. We study the problem of parameter…
Decoupling band topology from criticality in bosonic systems
Mariam Ughrelidze, Lorenza Viola, Emilio Cobanera
A new understanding of criticality in systems described by quadratic bosonic Hamiltonians (QBHs) ties the emergence of long-range correlations to boundaries of dynamical, not therm…
Separate and efficient characterization of state-preparation and measurement errors using single-qubit operations
Muhammad Qasim Khan, Leigh M. Norris, Lorenza Viola
In many platforms, errors from state-preparation and measurement (SPAM) dominate over single-qubit gate errors. To inform further hardware improvements and the development of more…
Quantum criticality beyond thermodynamic stability
Mariam Ughrelidze, Vincent P. Flynn, Emilio Cobanera +1
For a many-body system in equilibrium, described by a thermodynamically stable Hamiltonian, quantum criticality is associated with structural changes of the many-body ground state.…
Precision bounds for frequency estimation under collective dephasing and open-loop control
Francisco Riberi, Gerardo Paz-Silva, Lorenza Viola
Dephasing noise is a ubiquitous source of decoherence in current atomic sensors. We address the problem of entanglement-assisted frequency estimation subject to classical dephasing…
Approximate Reduced Lindblad Dynamics via Algebraic and Adiabatic Methods
Tommaso Grigoletto, Alain Sarlette, Francesco Ticozzi +1
We present an algebraic framework for approximate model reduction of Markovian open quantum dynamics that guarantees complete positivity and trace preservation by construction. Fir…