Legal Question in Real Estate Law in California

In theory, yes. As a practical matter, there are potential problems.

First, all California grant deeds contain, by statute, two implied warranties: (1) that the grantor has not previously conveyed any part of the property to someone else; and (2) the property is free from any encumbrance made or suffered by the grantor or anyone claiming under her.

If the property has been subject to a loan, repayment of the loan principal with community funds would give rise to a tiny (at first) but ever-increasing community-property interest, called in legal jargon a "pro tanto" interest. See the cases In re Marriage of Moore and In re Marriage of Marsden. So, if there has been a mortgage on the home, and either his earning or youe earnings were used to reduce principal, you and he each have less that a half interest as joint tenants, with the balance being held as community property. Family Code section 1102(a) requires both spouses (with limited exceptions) to join in executing any sale of community real property. So, you may not be able to convey a full half interest.

You'd be safer doing a quitclaim deed.

In addition, there are multiple worries, legal and practical, concerning splitting ownership of a residence other than between husband and wife. Who is getting the half (or thereabouts) interest, and why? If you are doing this for estate-planning purposes, there are certainly better plans (living trusts, for example). If this is a sale to a stranger, the price will almost certainly be well under half the fair market value of the property.

I recommend getting legal and financial (tax) advice before progressing very far with this concept.

Yes, there is no legal prohibition against it, but I would caution that there may be tax implications and other issues that arise as a result of it.