Institutional regime shift in intellectual property rights and innovation strategies of firms in China

This study develops a novel conceptual framework to understand the differential impact of formal institutional regime shift in intellectual property rights on the innovation and patenting strategies of Chinese and Western firms operating in China. We argue that to the extent that Chinese firms have been deeply embedded in China’s informal institutions, they are less responsive to formal institutional changes than Western firms operating in China. Using the major China patent law reform of 2001 as an exogenous event, we find results consistent with our key arguments: With the strengthening of the previously weak (utility model) patent protection, Chinese firms are less likely to apply for such patents to safeguard their innovations than Western firms. However, this difference becomes less pronounced in regions with higher quality intellectual property rights and legal institutions that foster research and development and innovation, and when Western firms gain longer operational experience in China. This study advances our understanding of the intricate interaction between formal and informal institutions and specifically how “stickiness” may arise in their substitutive relationship because of the embeddedness of firms in informal institutional environments. It also provides important implications for policy and innovation strategies for policy makers and firms in emerging economies. </jats:p

Scaling laws for the (de-)polarization time of relativistic particle beams in strong fields

The acceleration of polarized electrons and protons in strong laser and plasma fields is a very attractive option to obtain polarized beams in the GeV range. We investigate the feasibility of particle acceleration in strong fields without destroying an initial polarization, taking into account all relevant mechanisms that could cause polarization losses, i.e. the spin precession described by the T-BMT equation, the Sokolov-Ternov effect and the Stern-Gerlach force. Scaling laws for the (de-)polarization time caused by these effects reveal that the dominant polarization limiting effect is the rotation of the single particle spins around the local electromagnetic fields. We compare our findings to test-particle simulations for high energetic electrons moving in a homogeneous electric field. For high particle energies the observed depolarization times are in good agreement with the analytically estimated ones.Comment: 17 pages and 4 figure

Polarized electron-beam acceleration driven by vortex laser pulses

We propose a new approach based on an all-optical set-up for generating relativistic polarized electron beams via vortex Laguerre-Gaussian (LG) laser-driven wakefield acceleration. Using a pre-polarized gas target, we find that the topology of the vortex wakefield resolves the depolarization issue of the injected electrons. In full three-dimensional particle-in-cell simulations, incorporating the spin dynamics via the Thomas-Bargmann Michel Telegdi equation, the LG laser preserves the electron spin polarization by more than 80% at high beam charge and flux. The method releases the limit on beam flux for polarized electron acceleration and promises more than an order of magnitude boost in peak flux, as compared to Gaussian beams. These results suggest a promising table-top method to produce energetic polarized electron beams.Comment: We replace some results and revise some description