Exchange coupling between silicon donors: the crucial role of the central cell and mass anisotropy

Donors in silicon are now demonstrated as one of the leading candidates for implementing qubits and quantum information processing. Single qubit operations, measurements and long coherence times are firmly established, but progress on controlling two qubit interactions has been slower. One reason for this is that the inter donor exchange coupling has been predicted to oscillate with separation, making it hard to estimate in device designs. We present a multivalley effective mass theory of a donor pair in silicon, including both a central cell potential and the effective mass anisotropy intrinsic in the Si conduction band. We are able to accurately describe the single donor properties of valley-orbit coupling and the spatial extent of donor wave functions, highlighting the importance of fitting measured values of hyperfine coupling and the orbital energy of the $1s$ levels. Ours is a simple framework that can be applied flexibly to a range of experimental scenarios, but it is nonetheless able to provide fast and reliable predictions. We use it to estimate the exchange coupling between two donor electrons and we find a smoothing of its expected oscillations, and predict a monotonic dependence on separation if two donors are spaced precisely along the [100] direction.Comment: Published version. Corrected b and B values from previous versio

Accounting for major development costs incurred in development of new oil reserves

Call number: LD2668 .R4 1964 L99

A Progress Report on the Canadian Bill of Rights

When the Parliament of Canada enacted the Canadian Bill of Rights\u27 in 1960 it injected fresh authority into the judicial power of interpretation of federal laws. The process of interpretation of the Bill ofRights itself has been difficult for a judiciary trained to accept law as given and to take for granted the great creative periods and personalities of English law without regard to the fact that much if not most of the civil liberties tradition in English (and therefore Canadian) law was triggered by declaratory statutes like Magna Carta and the English Bill ofRights. The decade and a half of existence of the Canadian Bill of Rights has seen the important questions of interpretation go before the Supreme Court of Canada. A survey of where we have come along the path of a Canadian human rights jurisprudence, the reasons for the direction taken, and the possibilities for the future may be useful at this time

A Progress Report on the Canadian Bill of Rights

When the Parliament of Canada enacted the Canadian Bill of Rights\u27 in 1960 it injected fresh authority into the judicial power of interpretation of federal laws. The process of interpretation of the Bill ofRights itself has been difficult for a judiciary trained to accept law as given and to take for granted the great creative periods and personalities of English law without regard to the fact that much if not most of the civil liberties tradition in English (and therefore Canadian) law was triggered by declaratory statutes like Magna Carta and the English Bill ofRights. The decade and a half of existence of the Canadian Bill of Rights has seen the important questions of interpretation go before the Supreme Court of Canada. A survey of where we have come along the path of a Canadian human rights jurisprudence, the reasons for the direction taken, and the possibilities for the future may be useful at this time

A Progress Report on the Canadian Bill of Rights

When the Parliament of Canada enacted the Canadian Bill of Rights\u27 in 1960 it injected fresh authority into the judicial power of interpretation of federal laws. The process of interpretation of the Bill ofRights itself has been difficult for a judiciary trained to accept law as given and to take for granted the great creative periods and personalities of English law without regard to the fact that much if not most of the civil liberties tradition in English (and therefore Canadian) law was triggered by declaratory statutes like Magna Carta and the English Bill ofRights. The decade and a half of existence of the Canadian Bill of Rights has seen the important questions of interpretation go before the Supreme Court of Canada. A survey of where we have come along the path of a Canadian human rights jurisprudence, the reasons for the direction taken, and the possibilities for the future may be useful at this time

A Progress Report on the Canadian Bill of Rights

When the Parliament of Canada enacted the Canadian Bill of Rights\u27 in 1960 it injected fresh authority into the judicial power of interpretation of federal laws. The process of interpretation of the Bill ofRights itself has been difficult for a judiciary trained to accept law as given and to take for granted the great creative periods and personalities of English law without regard to the fact that much if not most of the civil liberties tradition in English (and therefore Canadian) law was triggered by declaratory statutes like Magna Carta and the English Bill ofRights. The decade and a half of existence of the Canadian Bill of Rights has seen the important questions of interpretation go before the Supreme Court of Canada. A survey of where we have come along the path of a Canadian human rights jurisprudence, the reasons for the direction taken, and the possibilities for the future may be useful at this time

A Progress Report on the Canadian Bill of Rights

When the Parliament of Canada enacted the Canadian Bill of Rights\u27 in 1960 it injected fresh authority into the judicial power of interpretation of federal laws. The process of interpretation of the Bill ofRights itself has been difficult for a judiciary trained to accept law as given and to take for granted the great creative periods and personalities of English law without regard to the fact that much if not most of the civil liberties tradition in English (and therefore Canadian) law was triggered by declaratory statutes like Magna Carta and the English Bill ofRights. The decade and a half of existence of the Canadian Bill of Rights has seen the important questions of interpretation go before the Supreme Court of Canada. A survey of where we have come along the path of a Canadian human rights jurisprudence, the reasons for the direction taken, and the possibilities for the future may be useful at this time