Ground state search in subspace with definite charge
Posted: 08 Nov 2018, 16:09
Hello everyone,
I have just started doing my first DMRG simulations and have some basic questions on how the algorithm works with MPS. As the documentation explains one should enable the mixer option of the algorithm to avoid getting stuck in local minima. Now let's say that I am looking for the ground state of a 1D spin Hamiltonian that preserves the total magnetization. If I perform standard DMRG without the mixer option, then the initial MPS sets the charge subspace I am looking into, as all the steps in the algorithm preserve the total charge of the MPS. As far as I understood, the mixer option brakes this property. Then, how can I look for the ground state in a given charge sector, making sure it is the real ground state? Is there an option that allows to use the mixer, but forcing the final state to be in a given charge sector?
Thank you in advance!
I have just started doing my first DMRG simulations and have some basic questions on how the algorithm works with MPS. As the documentation explains one should enable the mixer option of the algorithm to avoid getting stuck in local minima. Now let's say that I am looking for the ground state of a 1D spin Hamiltonian that preserves the total magnetization. If I perform standard DMRG without the mixer option, then the initial MPS sets the charge subspace I am looking into, as all the steps in the algorithm preserve the total charge of the MPS. As far as I understood, the mixer option brakes this property. Then, how can I look for the ground state in a given charge sector, making sure it is the real ground state? Is there an option that allows to use the mixer, but forcing the final state to be in a given charge sector?
Thank you in advance!