We suggest two types of experiments, NMR and macroscopic magnetometry, with solid PbTiO3 to search for the nuclear Schiff moment of 207 Pb. Both kinds of experiments promise substantial improvement over the presently achieved sensitivities. Statistical considerations show that the improvement of the current sensitivity can be up to 10 orders of magnitude for the magnetometry experiment and up to 6 orders of magnitude for the NMR experiment. Such significant enhancement is due to the strong internal electric field of the ferroelectric, as well as due to the possibility to cool the nuclear-spin subsystem in the compound down to nanokelvin temperatures. PACS numbers: 11.30.Er, 32.10.Dk, 67.80.Jd The existence of permanent electric dipole moment (EDM) of a quantum particle requires that fundamental parity (P) and time-reversal (T) symmetries are violated. By the CPT-theorem, this would also mean the violation of the combined CP (charge conjugation-parity) symmetry. Studies of T and CP violation in Nature provide valuable information for the theories of baryogenesis, and for our understanding of fundamental interactions in general. Thus, considerable effort has been put into searches for EDMs of particles, atoms and molecules.The current experimental upper limit on the neutron EDM is d n ≤ 6.3 × 10 −26 e cm [1]. Experiments with paramagnetic atoms and molecules, the most sensitive of which was performed with Tl atoms [2], provide upper limit on the electron EDM, d e ≤ 1.6 × 10 −27 e cm. The most sensitive experiment with diamagnetic atoms is performed with 199 Hg vapor [3]; it gives the upper limit on the EDM of 199 Hg atom d( 199 Hg) ≤ 2.1 × 10 −28 e cm. This EDM is mainly induced by the nuclear Schiff moment, S, which is usually defined by the P-and T-odd electrostatic potential it generates [4]:Atomic calculations [5,6] [12]. Since Xe atoms are diamagnetic, the measurement is mainly aimed at the 129 Xe nuclear Schiff moment. By statistical considerations only, the sensitivity of the experiment is d( 129 Xe) ∼ 3 × 10 −37 e cm for 10 days of averaging [12]. Taking into account the smaller nuclear charge of Xe, this effectively means improvement by 8 orders of magnitude when compared to the present result (2) for 199 Hg. The limitations because of the systematic effects are also discussed in Ref. [12]. The solid state experiment with gadolinium garnet, recently suggested by Lamoreaux [13] to measure the electron EDM, promises 5 order of magnitude improvement over the current Tl result (statistical estimate corresponding to 10 days of averaging.)In the present paper we suggest to use ferroelectric PbTiO 3 to measure Schiff moment of 207 Pb nucleus. Possibility to measure the macroscopic magnetization induced by electric field, as was suggested by Lamoreaux for gadolinium garnets [13], looks most promising because of the large internal electric field in ferroelectric. In addition, the nuclear-spin subsystem of the compound can be magnetically cooled down to nanokelvin temperatures. For a 10-day averaging, statisti...

Effects caused by the electron electric dipole moment (EDM) in gadolinium garnets are considered. Experimental studies of these effects could improve current upper limit on the electron EDM by several orders of magnitude. We suggest a consistent theoretical model and perform calculations of observable effects in gadolinium gallium garnet and gadolinium iron garnet. Our calculation accounts for both direct and exchange diagrams.

We suggest to use insulating garnets doped by rare earth ions for measurements of nuclear anapole moments. A parity violating shift of the NMR frequency arises due to the combined effect of the lattice crystal field and the anapole moment of the rare-earth nucleus.We show that there are two different observable effects related to frequency: 1) A shift of the NMR frequency in an external electric field applied to the solid. The value of the shift is about ∆ν1 ∼ 10 −5 Hz with E = 10 kV/cm; 2) A splitting of the NMR line into two lines. The second effect is independent of the external electric field. The value of the splitting is about ∆ν2 ∼ 0.5 Hz and it depends on the orientation of the crystal with respect to magnetic field. Both estimates are presented for a magnetic field of about 10 tesla.We also discuss a radiofrequency electric field and a static macroscopic magnetization caused by the nuclear anapole moment.

We demonstrate that parity-nonconserving interaction due to the nuclear weak charge Q W leads to a nonlinear magnetoelectric effect in centrosymmetric paramagnetic crystals. It is shown that the effect exists only in crystals with special symmetry axis k. Kinematically, the correlation ͑correction to energy͒ has the form H PNC ϰ Q W E · ͓B ϫ k͔͑B · k͒, where B and E are external magnetic and electric fields. This gives rise to the magnetic induction M PNC ϰ Q W ͕k͑B · ͓k ϫ E͔͒ + ͓k ϫ E͔͑B · k͖͒. To be specific, we consider rare-earth-metal trifluorides and, in particular, dysprosium trifluoride which looks the most suitable for experiment. We estimate the optimal temperature for the experiment to be of a few kelvin. For the magnetic field B = 1 T and the electric field E = 10 kV/ cm, the expected magnetic induction is 4M PNC ϳ 0.5ϫ 10 −11 G, six orders of magnitude larger than the best sensitivity currently under discussion. Dysprosium has several stable isotopes, and so comparison of the effects for different isotopes provides the possibility for precise measurement of the Weinberg angle.

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