PIRSA:07060015

Purifying qubits in NMR quantum information processing

APA

Ryan, C. (2007). Purifying qubits in NMR quantum information processing. Perimeter Institute. https://pirsa.org/07060015

MLA

Ryan, Colm. Purifying qubits in NMR quantum information processing. Perimeter Institute, Jun. 02, 2007, https://pirsa.org/07060015

BibTex

          @misc{ pirsa_PIRSA:07060015,
            doi = {10.48660/07060015},
            url = {https://pirsa.org/07060015},
            author = {Ryan, Colm},
            keywords = {Quantum Information},
            language = {en},
            title = {Purifying qubits in NMR quantum information processing},
            publisher = {Perimeter Institute},
            year = {2007},
            month = {jun},
            note = {PIRSA:07060015 see, \url{https://pirsa.org}}
          }
          

Colm Ryan Institute for Quantum Computing (IQC)

Abstract

Any implementation of  a quantum computer will require the ability to reset qubits to a pure input state, both to start the computation and more importantly to implement fault-tolerant operations.  Even if we cannot reset to a perfectly pure state, heat-bath algorithmic cooling provides a method of purifying mixed states.  By combining the ability to pump entropy out of the system through a controllable interaction with a heat bath and coherent control of the qubits, we are able to cool a subset of the qubits far below the heat bath temperature.  Here we show an implementation of this cooling in a solid state NMR quantum information processor which offers high fidelity control of the qubit system and controllable access to a heat bath.   We demonstrate an implementation of multiple rounds of heat-bath algorithmic cooling on three qubits and discuss the improvements in control techniques which have allowed us to show the purification of a single qubit to one and a half times the heat bath polarization.